<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019f8f48-3f90-7f4a-bb2d-f7d0bd0d4efe,g:be366162-0712-47e3-962a-34820281d7a6-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.wabtec.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="wab-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019f8f48-40f9-7061-8d26-0a7eaa9d609e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_StatementTable_019f8f48-40f9-7061-8d26-0a7eaa9d609e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f8f48-40f9-7906-86bf-29ec36d1244b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019f8f48-40f9-7061-8d26-0a7eaa9d609e" xlink:to="loc_srt_ProductOrServiceAxis_019f8f48-40f9-7906-86bf-29ec36d1244b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8f48-40f9-7906-86bf-29ec36d1244b_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f8f48-40f9-7906-86bf-29ec36d1244b" xlink:to="loc_srt_ProductsAndServicesDomain_019f8f48-40f9-7906-86bf-29ec36d1244b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8f48-40f9-7751-923c-1dadd659dc5f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f8f48-40f9-7906-86bf-29ec36d1244b" xlink:to="loc_srt_ProductsAndServicesDomain_019f8f48-40f9-7751-923c-1dadd659dc5f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_019f8f48-40f9-7b01-b564-5294caf2085c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-40f9-7751-923c-1dadd659dc5f" xlink:to="loc_us-gaap_ProductMember_019f8f48-40f9-7b01-b564-5294caf2085c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019f8f48-40f9-7a2d-bd97-e4ff428fbcd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-40f9-7751-923c-1dadd659dc5f" xlink:to="loc_us-gaap_ServiceMember_019f8f48-40f9-7a2d-bd97-e4ff428fbcd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_019f8f48-40f9-7181-b4d6-bab4572c2dd2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_RevenuesAbstract_019f8f48-40f9-7181-b4d6-bab4572c2dd2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f8f48-40f9-70ae-aac0-0cc7eef9ea00" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_019f8f48-40f9-7181-b4d6-bab4572c2dd2" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f8f48-40f9-70ae-aac0-0cc7eef9ea00" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019f8f48-40f9-734c-a092-0ab4af73da9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSoldAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019f8f48-40f9-734c-a092-0ab4af73da9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019f8f48-40f9-7459-9014-b5fa617131b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_019f8f48-40f9-734c-a092-0ab4af73da9a" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019f8f48-40f9-7459-9014-b5fa617131b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019f8f48-40f9-70cc-a201-fd850d49231d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_GrossProfit_019f8f48-40f9-70cc-a201-fd850d49231d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_019f8f48-40f9-7cf2-bb3d-6250d703db77" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_OperatingExpensesAbstract_019f8f48-40f9-7cf2-bb3d-6250d703db77" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019f8f48-40f9-7fd1-aa99-2c98ca5d1774" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f8f48-40f9-7cf2-bb3d-6250d703db77" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019f8f48-40f9-7fd1-aa99-2c98ca5d1774" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019f8f48-40f9-7f3f-8b3f-ebe69c898fcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f8f48-40f9-7cf2-bb3d-6250d703db77" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019f8f48-40f9-7f3f-8b3f-ebe69c898fcc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019f8f48-40f9-7b1a-8ddb-d7bccfea1c0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f8f48-40f9-7cf2-bb3d-6250d703db77" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019f8f48-40f9-7b1a-8ddb-d7bccfea1c0e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019f8f48-40f9-7b6c-a09f-7a995c941400" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_019f8f48-40f9-7cf2-bb3d-6250d703db77" xlink:to="loc_us-gaap_OperatingExpenses_019f8f48-40f9-7b6c-a09f-7a995c941400" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019f8f48-40f9-78b0-87e3-7f449481df5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_OperatingIncomeLoss_019f8f48-40f9-78b0-87e3-7f449481df5d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f8f48-40f9-7c42-b175-8c66909ff113" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f8f48-40f9-7c42-b175-8c66909ff113" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019f8f48-40f9-729e-862a-8af899928cd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f8f48-40f9-7c42-b175-8c66909ff113" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019f8f48-40f9-729e-862a-8af899928cd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019f8f48-40f9-74a4-b68a-6b38da750dd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_019f8f48-40f9-7c42-b175-8c66909ff113" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019f8f48-40f9-74a4-b68a-6b38da750dd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f8f48-40f9-78c6-b9e0-457274378d6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f8f48-40f9-78c6-b9e0-457274378d6c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019f8f48-40f9-70e7-9d4f-5b4c1b4043bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019f8f48-40f9-70e7-9d4f-5b4c1b4043bf" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019f8f48-40f9-7672-b182-bb6c3d2a65d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_ProfitLoss_019f8f48-40f9-7672-b182-bb6c3d2a65d5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f8f48-40f9-78e3-b1c9-b7c9b0189029" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f8f48-40f9-78e3-b1c9-b7c9b0189029" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f8f48-40f9-7daf-83bd-f90d9939956e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_NetIncomeLoss_019f8f48-40f9-7daf-83bd-f90d9939956e" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_019f8f48-40f9-7cb5-a796-21b41d118d5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_EarningsPerShareAbstract_019f8f48-40f9-7cb5-a796-21b41d118d5a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_019f8f48-40f9-7fcd-adf1-0a590e2ea9b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019f8f48-40f9-7cb5-a796-21b41d118d5a" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_019f8f48-40f9-7fcd-adf1-0a590e2ea9b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019f8f48-40f9-71bc-851f-b18bf0afcc97" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_019f8f48-40f9-7fcd-adf1-0a590e2ea9b7" xlink:to="loc_us-gaap_EarningsPerShareBasic_019f8f48-40f9-71bc-851f-b18bf0afcc97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_019f8f48-40f9-7ec0-8058-678be70f4023" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_019f8f48-40f9-7cb5-a796-21b41d118d5a" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_019f8f48-40f9-7ec0-8058-678be70f4023" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019f8f48-40f9-7a9e-b7d3-0206575db7d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_019f8f48-40f9-7ec0-8058-678be70f4023" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019f8f48-40f9-7a9e-b7d3-0206575db7d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019f8f48-40f9-7480-9525-1e2c93db3cfe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-40f9-770d-902a-acc3d44a8d45" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019f8f48-40f9-7480-9525-1e2c93db3cfe" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f8f48-40f9-7b86-8daa-24a4ba193aec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019f8f48-40f9-7480-9525-1e2c93db3cfe" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f8f48-40f9-7b86-8daa-24a4ba193aec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f8f48-40f9-75bc-bbc8-aa2d6cf32d31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_019f8f48-40f9-7480-9525-1e2c93db3cfe" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f8f48-40f9-75bc-bbc8-aa2d6cf32d31" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="wab-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f8f48-41c0-7a16-9fd0-78a9a3ece966" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019f8f48-41c0-7035-b5b0-db5ae9943590" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-41c0-7a16-9fd0-78a9a3ece966" xlink:to="loc_us-gaap_StatementTable_019f8f48-41c0-7035-b5b0-db5ae9943590" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-705b-b949-d9400eb6cf06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019f8f48-41c0-7035-b5b0-db5ae9943590" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-705b-b949-d9400eb6cf06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-705b-b949-d9400eb6cf06_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-705b-b949-d9400eb6cf06" xlink:to="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-705b-b949-d9400eb6cf06_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-705b-b949-d9400eb6cf06" xlink:to="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019f8f48-41c0-7fab-a081-706c8491a527" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:to="loc_us-gaap_CommonStockMember_019f8f48-41c0-7fab-a081-706c8491a527" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019f8f48-41c0-79e9-aec4-ce012638fdf8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019f8f48-41c0-79e9-aec4-ce012638fdf8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019f8f48-41c0-79c7-b8cb-8dbdc8d93f3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019f8f48-41c0-79c7-b8cb-8dbdc8d93f3a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019f8f48-41c0-75b9-af7a-1fbfb7533ca1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:to="loc_us-gaap_RetainedEarningsMember_019f8f48-41c0-75b9-af7a-1fbfb7533ca1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8f48-41c0-7cd7-9580-f05a80ed774e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8f48-41c0-7cd7-9580-f05a80ed774e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_019f8f48-41c0-7888-a374-7c1d1477b2cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7655-abe5-6f973d90412c" xlink:to="loc_us-gaap_NoncontrollingInterestMember_019f8f48-41c0-7888-a374-7c1d1477b2cb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8f48-41c0-7a16-9fd0-78a9a3ece966" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019f8f48-41c0-7462-a570-40cbc4c4ff30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_CommonStockSharesIssued_019f8f48-41c0-7462-a570-40cbc4c4ff30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f8f48-41c0-7950-a8e0-6b05428b1c27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f8f48-41c0-7950-a8e0-6b05428b1c27" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019f8f48-41c0-7885-ada2-8f55de133232" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019f8f48-41c0-7885-ada2-8f55de133232" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_019f8f48-41c0-73bf-8a9f-a0fcf9f47b16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_DividendsCommonStockCash_019f8f48-41c0-73bf-8a9f-a0fcf9f47b16" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_StockIssuedDuringPeriodValueStockOptionsExercisedNetOfTax_019f8f48-41c0-79da-b65f-ea97cfb0cf98" xlink:href="wab-20260930.xsd#wab_StockIssuedDuringPeriodValueStockOptionsExercisedNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_wab_StockIssuedDuringPeriodValueStockOptionsExercisedNetOfTax_019f8f48-41c0-79da-b65f-ea97cfb0cf98" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments_019f8f48-41c0-79f7-87fd-fc8a13aa5ba2" xlink:href="wab-20260930.xsd#wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments_019f8f48-41c0-79f7-87fd-fc8a13aa5ba2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f8f48-41c0-7f5c-8b7f-c7d167c808d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f8f48-41c0-7f5c-8b7f-c7d167c808d8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019f8f48-41c0-7019-9548-abbd37ccd155" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_ProfitLoss_019f8f48-41c0-7019-9548-abbd37ccd155" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019f8f48-41c0-7abf-b92f-aa991d47570e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019f8f48-41c0-7abf-b92f-aa991d47570e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_019f8f48-41c0-7dcc-bfc3-1377b59a13d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_019f8f48-41c0-7dcc-bfc3-1377b59a13d5" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019f8f48-41c0-7b4a-8051-2437ec0fa1f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019f8f48-41c0-7b4a-8051-2437ec0fa1f2" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_019f8f48-41c0-78fd-a7d3-7a64b57bbee0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_StockholdersEquityOther_019f8f48-41c0-78fd-a7d3-7a64b57bbee0" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_019f8f48-41c0-7c19-b5ee-59ba99b9a616" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_019f8f48-41c0-7c19-b5ee-59ba99b9a616" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f8f48-41c0-77ea-be68-41ca4cf20c00" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f8f48-41c0-77ea-be68-41ca4cf20c00" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f8f48-41c0-7e7d-a979-f9b5409e85b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8f48-41c0-7ea1-ad56-0326efdd6675" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f8f48-41c0-7e7d-a979-f9b5409e85b1" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019f8f48-41c0-7a57-83a7-b0e18ed2f208" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f8f48-41c0-7fda-accc-821a21beaac2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019f8f48-41c0-7406-a88e-e7943df2d7d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/ACCOUNTINGPOLICIESRemainingPerformanceObligationsDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#ACCOUNTINGPOLICIESRemainingPerformanceObligationsDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/ACCOUNTINGPOLICIESRemainingPerformanceObligationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8f48-41c0-7a8a-98cd-e6d51f251f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8f48-41c0-7a8a-98cd-e6d51f251f9d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f8f48-41c0-7e90-b176-c88f1d3b2d2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8f48-41c0-7a8a-98cd-e6d51f251f9d" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f8f48-41c0-7e90-b176-c88f1d3b2d2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019f8f48-41c0-73e9-b923-68eee126879d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019f8f48-41c0-73e9-b923-68eee126879d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8f48-41c0-75d9-96da-2d68961ce6fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8f48-41c0-75d9-96da-2d68961ce6fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8f48-41c0-7ae2-8546-87db7a45ba0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8f48-41c0-7ae2-8546-87db7a45ba0c" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/ACCOUNTINGPOLICIESRemainingPerformanceObligationsDetails_1" xlink:type="simple" xlink:href="wab-20260930.xsd#ACCOUNTINGPOLICIESRemainingPerformanceObligationsDetails_1"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/ACCOUNTINGPOLICIESRemainingPerformanceObligationsDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8f48-41c0-7a8a-98cd-e6d51f251f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8f48-41c0-7a8a-98cd-e6d51f251f9d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019f8f48-41c0-73e9-b923-68eee126879d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019f8f48-41c0-73e9-b923-68eee126879d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8f48-41c0-75d9-96da-2d68961ce6fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8f48-41c0-75d9-96da-2d68961ce6fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8f48-41c0-7ae2-8546-87db7a45ba0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8f48-41c0-73a0-952b-2e76d5af6db6" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8f48-41c0-7ae2-8546-87db7a45ba0c" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/ACCOUNTINGPOLICIESAdditionalInformationDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#ACCOUNTINGPOLICIESAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/ACCOUNTINGPOLICIESAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019f8f48-41c0-7a5a-a275-a271c740be9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019f8f48-41c0-7a5a-a275-a271c740be9e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_019f8f48-41c0-7a88-9d65-87c9afc6e33f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019f8f48-41c0-7a5a-a275-a271c740be9e" xlink:to="loc_us-gaap_CollateralAxis_019f8f48-41c0-7a88-9d65-87c9afc6e33f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_019f8f48-41c0-7a88-9d65-87c9afc6e33f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_019f8f48-41c0-7a88-9d65-87c9afc6e33f" xlink:to="loc_us-gaap_CollateralDomain_019f8f48-41c0-7a88-9d65-87c9afc6e33f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_019f8f48-41c0-753f-aedf-1a555f1afd73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_019f8f48-41c0-7a88-9d65-87c9afc6e33f" xlink:to="loc_us-gaap_CollateralDomain_019f8f48-41c0-753f-aedf-1a555f1afd73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralPledgedMember_019f8f48-41c0-7d46-a140-fc64d933e4a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralPledgedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_019f8f48-41c0-753f-aedf-1a555f1afd73" xlink:to="loc_us-gaap_CollateralPledgedMember_019f8f48-41c0-7d46-a140-fc64d933e4a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f8f48-41c0-761e-a36d-3236186aa99d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019f8f48-41c0-7a5a-a275-a271c740be9e" xlink:to="loc_srt_RangeAxis_019f8f48-41c0-761e-a36d-3236186aa99d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8f48-41c0-761e-a36d-3236186aa99d_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019f8f48-41c0-761e-a36d-3236186aa99d" xlink:to="loc_srt_RangeMember_019f8f48-41c0-761e-a36d-3236186aa99d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8f48-41c0-71c0-bee3-dec8f30c0a26" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019f8f48-41c0-761e-a36d-3236186aa99d" xlink:to="loc_srt_RangeMember_019f8f48-41c0-71c0-bee3-dec8f30c0a26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f8f48-41c0-70fb-9210-c44e35d33093" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8f48-41c0-71c0-bee3-dec8f30c0a26" xlink:to="loc_srt_MinimumMember_019f8f48-41c0-70fb-9210-c44e35d33093" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f8f48-41c0-7fe6-ae33-1cd68b9aa719" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8f48-41c0-71c0-bee3-dec8f30c0a26" xlink:to="loc_srt_MaximumMember_019f8f48-41c0-7fe6-ae33-1cd68b9aa719" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AccountReceivableSecuritizationFacilityMaximumAmount_019f8f48-41c0-736d-a8e7-78a6d8e395db" xlink:href="wab-20260930.xsd#wab_AccountReceivableSecuritizationFacilityMaximumAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_wab_AccountReceivableSecuritizationFacilityMaximumAmount_019f8f48-41c0-736d-a8e7-78a6d8e395db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019f8f48-41c0-7bde-b08f-11668c486b4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019f8f48-41c0-7bde-b08f-11668c486b4d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromRepaymentsOfAccountsReceivableSecuritization_019f8f48-41c0-7308-baae-10c8b6c554d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromRepaymentsOfAccountsReceivableSecuritization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_us-gaap_ProceedsFromRepaymentsOfAccountsReceivableSecuritization_019f8f48-41c0-7308-baae-10c8b6c554d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_019f8f48-41c0-797d-9794-b00b5e517e93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_us-gaap_RestrictedCash_019f8f48-41c0-797d-9794-b00b5e517e93" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesRetired_019f8f48-41c0-7e1b-9d74-fc3daf04394c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockSharesRetired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_us-gaap_TreasuryStockSharesRetired_019f8f48-41c0-7e1b-9d74-fc3daf04394c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramPaymentTimingPeriod_019f8f48-41c0-7e2c-8a27-97f6740d036a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramPaymentTimingPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_us-gaap_SupplierFinanceProgramPaymentTimingPeriod_019f8f48-41c0-7e2c-8a27-97f6740d036a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramObligation_019f8f48-41c0-71c0-b600-3b863a9ba52c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019f8f48-41c0-78f3-8de0-2aaa227d2c2a" xlink:to="loc_us-gaap_SupplierFinanceProgramObligation_019f8f48-41c0-71c0-b600-3b863a9ba52c" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/ACCOUNTINGPOLICIESScheduleofChangesinAccumulatedOtherComprehensiveLossbyComponentNetofTaxDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#ACCOUNTINGPOLICIESScheduleofChangesinAccumulatedOtherComprehensiveLossbyComponentNetofTaxDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/ACCOUNTINGPOLICIESScheduleofChangesinAccumulatedOtherComprehensiveLossbyComponentNetofTaxDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019f8f48-41c0-770d-af44-0cc31bafadf3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019f8f48-41c0-771f-8786-4519363b75ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019f8f48-41c0-770d-af44-0cc31bafadf3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019f8f48-41c0-771f-8786-4519363b75ff" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-7628-a6e1-fe314fc9836c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019f8f48-41c0-771f-8786-4519363b75ff" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-7628-a6e1-fe314fc9836c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7628-a6e1-fe314fc9836c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-7628-a6e1-fe314fc9836c" xlink:to="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7628-a6e1-fe314fc9836c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7924-bf56-22309166d2de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019f8f48-41c0-7628-a6e1-fe314fc9836c" xlink:to="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7924-bf56-22309166d2de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8f48-41c0-77b0-9773-763a2b65f906" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8f48-41c0-7924-bf56-22309166d2de" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8f48-41c0-77b0-9773-763a2b65f906" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019f8f48-41c0-7675-ad64-d70244781f25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8f48-41c0-77b0-9773-763a2b65f906" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019f8f48-41c0-7675-ad64-d70244781f25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019f8f48-41c0-761f-90a9-bd5dbd0c5606" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8f48-41c0-77b0-9773-763a2b65f906" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019f8f48-41c0-761f-90a9-bd5dbd0c5606" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019f8f48-41c0-7318-aee4-8f7b451c1109" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8f48-41c0-77b0-9773-763a2b65f906" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019f8f48-41c0-7318-aee4-8f7b451c1109" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f8f48-41c0-773b-8f41-091e69f9e8f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019f8f48-41c0-770d-af44-0cc31bafadf3" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f8f48-41c0-773b-8f41-091e69f9e8f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f8f48-41c0-70d2-93de-cab4be00c49a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f8f48-41c0-773b-8f41-091e69f9e8f2" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f8f48-41c0-70d2-93de-cab4be00c49a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019f8f48-41c0-7e64-a9d2-dbdf30c3c7bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f8f48-41c0-773b-8f41-091e69f9e8f2" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019f8f48-41c0-7e64-a9d2-dbdf30c3c7bf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019f8f48-41c0-70a1-a490-caf7ae5bee5f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f8f48-41c0-773b-8f41-091e69f9e8f2" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019f8f48-41c0-70a1-a490-caf7ae5bee5f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f8f48-41c0-7be5-a465-5ba6aacd0d4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019f8f48-41c0-773b-8f41-091e69f9e8f2" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f8f48-41c0-7be5-a465-5ba6aacd0d4a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f8f48-41c0-7229-9308-0ab014f25caf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/ACQUISITIONSAdditionalInformationDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#ACQUISITIONSAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/ACQUISITIONSAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-713e-a4ff-2e77d9070e5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-713e-a4ff-2e77d9070e5a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-713e-a4ff-2e77d9070e5a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-762b-932a-db97f42af853_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-762b-932a-db97f42af853_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DellnerCouplersMember_019f8f48-41c0-7619-9140-83ed5075a3d4" xlink:href="wab-20260930.xsd#wab_DellnerCouplersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:to="loc_wab_DellnerCouplersMember_019f8f48-41c0-7619-9140-83ed5075a3d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-73b2-a90a-22da31cf835e" xlink:href="wab-20260930.xsd#wab_FrauscherSensorTechnologyGroupGmbHMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:to="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-73b2-a90a-22da31cf835e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_InspectionTechnologiesMember_019f8f48-41c0-72f7-a1b8-7ab22cc3a858" xlink:href="wab-20260930.xsd#wab_InspectionTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:to="loc_wab_InspectionTechnologiesMember_019f8f48-41c0-72f7-a1b8-7ab22cc3a858" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f8f48-41c0-7725-b83a-568eabca3461" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-713e-a4ff-2e77d9070e5a" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f8f48-41c0-7725-b83a-568eabca3461" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f8f48-41c0-7b3a-be7d-b79b4d786c49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f8f48-41c0-7b3a-be7d-b79b4d786c49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f8f48-41c0-71dc-ab3f-4c9047d7b91d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f8f48-41c0-71dc-ab3f-4c9047d7b91d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationAcquisitionsCompleted_019f8f48-41c0-7fda-b9c0-fd953ee035f5" xlink:href="wab-20260930.xsd#wab_BusinessCombinationAcquisitionsCompleted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_wab_BusinessCombinationAcquisitionsCompleted_019f8f48-41c0-7fda-b9c0-fd953ee035f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8f48-41c0-7221-8706-c777182ce58d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8f48-41c0-7221-8706-c777182ce58d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/ACQUISITIONSAdditionalInformationDetails_1" xlink:type="simple" xlink:href="wab-20260930.xsd#ACQUISITIONSAdditionalInformationDetails_1"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/ACQUISITIONSAdditionalInformationDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-713e-a4ff-2e77d9070e5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-713e-a4ff-2e77d9070e5a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-713e-a4ff-2e77d9070e5a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-762b-932a-db97f42af853_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-762b-932a-db97f42af853_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-762b-932a-db97f42af853" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DellnerCouplersMember_019f8f48-41c0-7619-9140-83ed5075a3d4" xlink:href="wab-20260930.xsd#wab_DellnerCouplersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:to="loc_wab_DellnerCouplersMember_019f8f48-41c0-7619-9140-83ed5075a3d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-73b2-a90a-22da31cf835e" xlink:href="wab-20260930.xsd#wab_FrauscherSensorTechnologyGroupGmbHMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:to="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-73b2-a90a-22da31cf835e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_InspectionTechnologiesMember_019f8f48-41c0-72f7-a1b8-7ab22cc3a858" xlink:href="wab-20260930.xsd#wab_InspectionTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-716d-92be-287ee4c719ec" xlink:to="loc_wab_InspectionTechnologiesMember_019f8f48-41c0-72f7-a1b8-7ab22cc3a858" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f8f48-41c0-7b3a-be7d-b79b4d786c49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f8f48-41c0-7b3a-be7d-b79b4d786c49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f8f48-41c0-71dc-ab3f-4c9047d7b91d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_019f8f48-41c0-71dc-ab3f-4c9047d7b91d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationAcquisitionsCompleted_019f8f48-41c0-7fda-b9c0-fd953ee035f5" xlink:href="wab-20260930.xsd#wab_BusinessCombinationAcquisitionsCompleted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_wab_BusinessCombinationAcquisitionsCompleted_019f8f48-41c0-7fda-b9c0-fd953ee035f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8f48-41c0-7221-8706-c777182ce58d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7ea3-a4f6-c5552921a719" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019f8f48-41c0-7221-8706-c777182ce58d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/ACQUISITIONSScheduleofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#ACQUISITIONSScheduleofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/ACQUISITIONSScheduleofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7deb-9fca-5dc728aac4ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-7a4c-96a1-e76c6a0d999a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7deb-9fca-5dc728aac4ab" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-7a4c-96a1-e76c6a0d999a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7c46-8907-18cab8405b47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019f8f48-41c0-7a4c-96a1-e76c6a0d999a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7c46-8907-18cab8405b47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7c46-8907-18cab8405b47_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7c46-8907-18cab8405b47" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7c46-8907-18cab8405b47_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7eb5-a152-b5356e7d526b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7c46-8907-18cab8405b47" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7eb5-a152-b5356e7d526b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DellnerCouplersMember_019f8f48-41c0-7c51-9013-dc7659a7f81e" xlink:href="wab-20260930.xsd#wab_DellnerCouplersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7eb5-a152-b5356e7d526b" xlink:to="loc_wab_DellnerCouplersMember_019f8f48-41c0-7c51-9013-dc7659a7f81e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-7db9-ade8-117611d9bd88" xlink:href="wab-20260930.xsd#wab_FrauscherSensorTechnologyGroupGmbHMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7eb5-a152-b5356e7d526b" xlink:to="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-7db9-ade8-117611d9bd88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_InspectionTechnologiesMember_019f8f48-41c0-7cf5-9cbe-e882d2b00c1b" xlink:href="wab-20260930.xsd#wab_InspectionTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7eb5-a152-b5356e7d526b" xlink:to="loc_wab_InspectionTechnologiesMember_019f8f48-41c0-7cf5-9cbe-e882d2b00c1b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7deb-9fca-5dc728aac4ab" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019f8f48-41c0-71be-b57e-30f4f3fc74ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019f8f48-41c0-71be-b57e-30f4f3fc74ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019f8f48-41c0-762a-8df9-94a3c2016d12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019f8f48-41c0-762a-8df9-94a3c2016d12" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_019f8f48-41c0-7482-980a-d5f2c3b5df0b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_019f8f48-41c0-7482-980a-d5f2c3b5df0b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_019f8f48-41c0-70d4-931e-c4fb46526d1d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_019f8f48-41c0-70d4-931e-c4fb46526d1d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019f8f48-41c0-796d-b1b1-a1afa2106445" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019f8f48-41c0-796d-b1b1-a1afa2106445" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f8f48-41c0-785e-9d7c-cf9ded1fd867" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_Goodwill_019f8f48-41c0-785e-9d7c-cf9ded1fd867" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationRecognizedAssetAcquiredCustomerRelationships_019f8f48-41c0-7380-95ce-d25e3977faee" xlink:href="wab-20260930.xsd#wab_BusinessCombinationRecognizedAssetAcquiredCustomerRelationships"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_wab_BusinessCombinationRecognizedAssetAcquiredCustomerRelationships_019f8f48-41c0-7380-95ce-d25e3977faee" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationRecognizedAssetAcquiredTradeNames_019f8f48-41c0-714c-b15d-770969332d61" xlink:href="wab-20260930.xsd#wab_BusinessCombinationRecognizedAssetAcquiredTradeNames"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_wab_BusinessCombinationRecognizedAssetAcquiredTradeNames_019f8f48-41c0-714c-b15d-770969332d61" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_019f8f48-41c0-7f23-b31d-802e36844b49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_019f8f48-41c0-7f23-b31d-802e36844b49" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_019f8f48-41c0-735a-a6a2-a71d70b77dd8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_019f8f48-41c0-735a-a6a2-a71d70b77dd8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill_019f8f48-41c0-7644-b0b6-b52b2cdab6e7" xlink:href="wab-20260930.xsd#wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_019f8f48-41c0-7e8c-83e9-435ee9f69ea8" xlink:to="loc_wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill_019f8f48-41c0-7644-b0b6-b52b2cdab6e7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019f8f48-41c0-7afc-b948-21eb44061541" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7deb-9fca-5dc728aac4ab" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019f8f48-41c0-7afc-b948-21eb44061541" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_019f8f48-41c0-71c6-81e7-667179f26ed3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019f8f48-41c0-7afc-b948-21eb44061541" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_019f8f48-41c0-71c6-81e7-667179f26ed3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_019f8f48-41c0-7900-9b0a-a0b28a318df2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019f8f48-41c0-7afc-b948-21eb44061541" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_019f8f48-41c0-7900-9b0a-a0b28a318df2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019f8f48-41c0-7a86-ad66-71f6c0d1bb06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_019f8f48-41c0-7afc-b948-21eb44061541" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019f8f48-41c0-7a86-ad66-71f6c0d1bb06" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f8f48-41c0-77b4-8ab8-1b34c05f5936" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8f48-41c0-7deb-9fca-5dc728aac4ab" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019f8f48-41c0-77b4-8ab8-1b34c05f5936" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofChangeintheCarryingAmountofGoodwillbySegmentDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#GOODWILLANDINTANGIBLEASSETSScheduleofChangeintheCarryingAmountofGoodwillbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofChangeintheCarryingAmountofGoodwillbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019f8f48-41c0-7e28-850e-29d6874d4c6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_019f8f48-41c0-7040-b15f-d86fef767c15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_019f8f48-41c0-7e28-850e-29d6874d4c6f" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019f8f48-41c0-7040-b15f-d86fef767c15" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-739c-8eb0-4dddcb29c2c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_019f8f48-41c0-7040-b15f-d86fef767c15" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-739c-8eb0-4dddcb29c2c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-739c-8eb0-4dddcb29c2c4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-739c-8eb0-4dddcb29c2c4" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-739c-8eb0-4dddcb29c2c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-7200-98e3-6470a6642a35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-739c-8eb0-4dddcb29c2c4" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-7200-98e3-6470a6642a35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_019f8f48-41c0-715c-83a1-1cbde8cf7fa5" xlink:href="wab-20260930.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7200-98e3-6470a6642a35" xlink:to="loc_wab_FreightSegmentMember_019f8f48-41c0-715c-83a1-1cbde8cf7fa5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_019f8f48-41c0-74b6-9fa3-a5ec300a6e9c" xlink:href="wab-20260930.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7200-98e3-6470a6642a35" xlink:to="loc_wab_TransitSegmentMember_019f8f48-41c0-74b6-9fa3-a5ec300a6e9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019f8f48-41c0-77ff-90e5-05ea0a688f93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019f8f48-41c0-7e28-850e-29d6874d4c6f" xlink:to="loc_us-gaap_GoodwillRollForward_019f8f48-41c0-77ff-90e5-05ea0a688f93" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f8f48-41c0-7750-a120-dfe73332c8e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019f8f48-41c0-77ff-90e5-05ea0a688f93" xlink:to="loc_us-gaap_Goodwill_019f8f48-41c0-7750-a120-dfe73332c8e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019f8f48-41c0-72c3-85e9-b5a7e6734af9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019f8f48-41c0-77ff-90e5-05ea0a688f93" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019f8f48-41c0-72c3-85e9-b5a7e6734af9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019f8f48-41c0-7220-b5cb-1baa6c16bb9f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_019f8f48-41c0-77ff-90e5-05ea0a688f93" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019f8f48-41c0-7220-b5cb-1baa6c16bb9f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f8f48-41c0-7534-a2f0-9f85a27037b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/GOODWILLANDINTANGIBLEASSETSAdditionalInformationDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#GOODWILLANDINTANGIBLEASSETSAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/GOODWILLANDINTANGIBLEASSETSAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019f8f48-41c0-7301-9b68-71bddc7c8db5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_019f8f48-41c0-7131-a967-482c868a6788" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019f8f48-41c0-7301-9b68-71bddc7c8db5" xlink:to="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_019f8f48-41c0-7131-a967-482c868a6788" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-70e2-a83b-9977e3b0867a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_019f8f48-41c0-7131-a967-482c868a6788" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-70e2-a83b-9977e3b0867a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-70e2-a83b-9977e3b0867a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-70e2-a83b-9977e3b0867a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-70e2-a83b-9977e3b0867a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-7ba1-8612-e0bb6863703d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-70e2-a83b-9977e3b0867a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-7ba1-8612-e0bb6863703d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_019f8f48-41c0-71df-a8a8-64a315487eb7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-7ba1-8612-e0bb6863703d" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_019f8f48-41c0-71df-a8a8-64a315487eb7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019f8f48-41c0-7d46-a61b-381c79544249" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-7ba1-8612-e0bb6863703d" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019f8f48-41c0-7d46-a61b-381c79544249" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f8f48-41c0-7f02-98e3-a4d5746eabca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-7ba1-8612-e0bb6863703d" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f8f48-41c0-7f02-98e3-a4d5746eabca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedTrademarks_019f8f48-41c0-7a4b-abe9-7cac648ce012" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndefiniteLivedTrademarks"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019f8f48-41c0-7301-9b68-71bddc7c8db5" xlink:to="loc_us-gaap_IndefiniteLivedTrademarks_019f8f48-41c0-7a4b-abe9-7cac648ce012" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019f8f48-41c0-70e0-a3c3-73f322c0a0a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019f8f48-41c0-7301-9b68-71bddc7c8db5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_019f8f48-41c0-70e0-a3c3-73f322c0a0a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019f8f48-41c0-73a8-a163-728eb52a9fcb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019f8f48-41c0-7301-9b68-71bddc7c8db5" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019f8f48-41c0-73a8-a163-728eb52a9fcb" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofIntangibleAssetsoftheCompanyOtherThanGoodwillandTradeNamesDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#GOODWILLANDINTANGIBLEASSETSScheduleofIntangibleAssetsoftheCompanyOtherThanGoodwillandTradeNamesDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/GOODWILLANDINTANGIBLEASSETSScheduleofIntangibleAssetsoftheCompanyOtherThanGoodwillandTradeNamesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f8f48-41c0-747b-b537-890ffd304699" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019f8f48-41c0-73c9-9f54-a5eed86b36b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f8f48-41c0-747b-b537-890ffd304699" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019f8f48-41c0-73c9-9f54-a5eed86b36b3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-740b-bafc-683368f52897" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019f8f48-41c0-73c9-9f54-a5eed86b36b3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-740b-bafc-683368f52897" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-740b-bafc-683368f52897_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-740b-bafc-683368f52897" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-740b-bafc-683368f52897_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-732f-a902-8dd9a9f550cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8f48-41c0-740b-bafc-683368f52897" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-732f-a902-8dd9a9f550cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_019f8f48-41c0-7794-b8e2-615b21c676cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-732f-a902-8dd9a9f550cd" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_019f8f48-41c0-7794-b8e2-615b21c676cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019f8f48-41c0-7e1c-a63b-61022b2a9d77" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-732f-a902-8dd9a9f550cd" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019f8f48-41c0-7e1c-a63b-61022b2a9d77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f8f48-41c0-7c7f-8b05-2d094b258635" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8f48-41c0-732f-a902-8dd9a9f550cd" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_019f8f48-41c0-7c7f-8b05-2d094b258635" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f8f48-41c0-7a8c-b2a1-b1879225acfc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f8f48-41c0-747b-b537-890ffd304699" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019f8f48-41c0-7a8c-b2a1-b1879225acfc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019f8f48-41c0-71d0-a35e-ef8749319164" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f8f48-41c0-747b-b537-890ffd304699" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019f8f48-41c0-71d0-a35e-ef8749319164" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019f8f48-41c0-722f-aa03-6152b8d98162" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019f8f48-41c0-747b-b537-890ffd304699" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019f8f48-41c0-722f-aa03-6152b8d98162" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/LONGTERMDEBTScheduleofLongtermDebtDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#LONGTERMDEBTScheduleofLongtermDebtDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/LONGTERMDEBTScheduleofLongtermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7a13-90d0-7ca3831f5bd1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:to="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7a13-90d0-7ca3831f5bd1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7f14-b539-2e68d2f686a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7a13-90d0-7ca3831f5bd1" xlink:to="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7f14-b539-2e68d2f686a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7f14-b539-2e68d2f686a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7f14-b539-2e68d2f686a2" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7f14-b539-2e68d2f686a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-73b7-96b9-6ac4cb2388d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7f14-b539-2e68d2f686a2" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-73b7-96b9-6ac4cb2388d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019f8f48-41c0-7a87-9b1e-1a89a81b6d77" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-73b7-96b9-6ac4cb2388d6" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019f8f48-41c0-7a87-9b1e-1a89a81b6d77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019f8f48-41c0-7081-a121-d33285c9bfef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-73b7-96b9-6ac4cb2388d6" xlink:to="loc_us-gaap_SecuredDebtMember_019f8f48-41c0-7081-a121-d33285c9bfef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7352-ba48-4a289e2f5fea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7a13-90d0-7ca3831f5bd1" xlink:to="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7352-ba48-4a289e2f5fea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7352-ba48-4a289e2f5fea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7352-ba48-4a289e2f5fea" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7352-ba48-4a289e2f5fea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7352-ba48-4a289e2f5fea" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A2025CreditAgreementMember_019f8f48-41c0-7607-b5a0-906ff11461ac" xlink:href="wab-20260930.xsd#wab_A2025CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A2025CreditAgreementMember_019f8f48-41c0-7607-b5a0-906ff11461ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A2025TermCreditAgreementMember_019f8f48-41c0-75c6-957e-7e90aaa17dda" xlink:href="wab-20260930.xsd#wab_A2025TermCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A2025TermCreditAgreementMember_019f8f48-41c0-75c6-957e-7e90aaa17dda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_019f8f48-41c0-793a-b1e8-eceed2321e1d" xlink:href="wab-20260930.xsd#wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_019f8f48-41c0-793a-b1e8-eceed2321e1d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A125PercentEuroNotesDueTwoThousandAndTwentySevenMember_019f8f48-41c0-7e89-a476-f5f8cdea76b0" xlink:href="wab-20260930.xsd#wab_A125PercentEuroNotesDueTwoThousandAndTwentySevenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A125PercentEuroNotesDueTwoThousandAndTwentySevenMember_019f8f48-41c0-7e89-a476-f5f8cdea76b0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentyEightMember_019f8f48-41c0-79e6-9032-9db3191d4168" xlink:href="wab-20260930.xsd#wab_A470PercentSeniorNotesDueTwoThousandAndTwentyEightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentyEightMember_019f8f48-41c0-79e6-9032-9db3191d4168" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4.90PercentSeniorNotesDueTwoThousandAndThirtyMember_019f8f48-41c0-7e5d-a9dd-85282c5ad4bb" xlink:href="wab-20260930.xsd#wab_A4.90PercentSeniorNotesDueTwoThousandAndThirtyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A4.90PercentSeniorNotesDueTwoThousandAndThirtyMember_019f8f48-41c0-7e5d-a9dd-85282c5ad4bb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A5.611PercentSeniorNotesDueTwoThousandAndThirtyFourMember_019f8f48-41c0-7ef1-97f4-ee7c5fa0ab01" xlink:href="wab-20260930.xsd#wab_A5.611PercentSeniorNotesDueTwoThousandAndThirtyFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A5.611PercentSeniorNotesDueTwoThousandAndThirtyFourMember_019f8f48-41c0-7ef1-97f4-ee7c5fa0ab01" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A5.50PercentSeniorNotesDueTwoThousandAndThirtyFiveMember_019f8f48-41c0-71e8-8ba8-bef47a0a1383" xlink:href="wab-20260930.xsd#wab_A5.50PercentSeniorNotesDueTwoThousandAndThirtyFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_A5.50PercentSeniorNotesDueTwoThousandAndThirtyFiveMember_019f8f48-41c0-71e8-8ba8-bef47a0a1383" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RevolvingReceivablesProgramMember_019f8f48-41c0-72a4-b21a-c387f4348084" xlink:href="wab-20260930.xsd#wab_RevolvingReceivablesProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-72cc-98a8-e4874299bb15" xlink:to="loc_wab_RevolvingReceivablesProgramMember_019f8f48-41c0-72a4-b21a-c387f4348084" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7b8f-83cf-8493a72a8e4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7a13-90d0-7ca3831f5bd1" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7b8f-83cf-8493a72a8e4a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7b8f-83cf-8493a72a8e4a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7b8f-83cf-8493a72a8e4a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7b8f-83cf-8493a72a8e4a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-714b-854e-ef0fa86b4b1d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7b8f-83cf-8493a72a8e4a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-714b-854e-ef0fa86b4b1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019f8f48-41c0-7c27-96a0-7038275a5116" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-714b-854e-ef0fa86b4b1d" xlink:to="loc_us-gaap_LineOfCreditMember_019f8f48-41c0-7c27-96a0-7038275a5116" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019f8f48-41c0-70f6-bf82-52541ac80b6a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-714b-854e-ef0fa86b4b1d" xlink:to="loc_us-gaap_SeniorNotesMember_019f8f48-41c0-70f6-bf82-52541ac80b6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_019f8f48-41c0-78e1-98f0-a95ffca9d8f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-714b-854e-ef0fa86b4b1d" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_019f8f48-41c0-78e1-98f0-a95ffca9d8f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_019f8f48-41c0-7652-b2a0-0cf9842f74fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7a13-90d0-7ca3831f5bd1" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_019f8f48-41c0-7652-b2a0-0cf9842f74fb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019f8f48-41c0-7652-b2a0-0cf9842f74fb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019f8f48-41c0-7652-b2a0-0cf9842f74fb" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019f8f48-41c0-7652-b2a0-0cf9842f74fb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019f8f48-41c0-78ef-92f0-2f2aebc4d158" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_019f8f48-41c0-7652-b2a0-0cf9842f74fb" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019f8f48-41c0-78ef-92f0-2f2aebc4d158" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019f8f48-41c0-74b9-aa10-4ae6ada25298" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_019f8f48-41c0-78ef-92f0-2f2aebc4d158" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019f8f48-41c0-74b9-aa10-4ae6ada25298" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019f8f48-41c0-7cec-9df5-e710fed41287" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_019f8f48-41c0-74b9-aa10-4ae6ada25298" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_019f8f48-41c0-7cec-9df5-e710fed41287" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f8f48-41c0-7fb0-9a5d-25bddc1db057" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f8f48-41c0-7fb0-9a5d-25bddc1db057" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019f8f48-41c0-7c59-bf18-a71a5a0be5ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_019f8f48-41c0-7c59-bf18-a71a5a0be5ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019f8f48-41c0-7933-9a28-9672d5d676ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019f8f48-41c0-7933-9a28-9672d5d676ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019f8f48-41c0-7068-b57c-07beefa49225" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:to="loc_us-gaap_LongTermDebt_019f8f48-41c0-7068-b57c-07beefa49225" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_019f8f48-41c0-7450-bee5-2bae17eb00ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:to="loc_us-gaap_LongTermDebtCurrent_019f8f48-41c0-7450-bee5-2bae17eb00ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019f8f48-41c0-7c1b-9dac-94aea70e651a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7f1c-9b21-36fcf8d01bca" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019f8f48-41c0-7c1b-9dac-94aea70e651a" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#LONGTERMDEBTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-74eb-9d26-0ad13a31dd17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-74eb-9d26-0ad13a31dd17" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7fe1-bdc7-a6d46a43f070" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-74eb-9d26-0ad13a31dd17" xlink:to="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7fe1-bdc7-a6d46a43f070" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7fe1-bdc7-a6d46a43f070_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7fe1-bdc7-a6d46a43f070" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7fe1-bdc7-a6d46a43f070_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7bea-a35f-7d0a87a7e101" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-7fe1-bdc7-a6d46a43f070" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7bea-a35f-7d0a87a7e101" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019f8f48-41c0-7874-a7eb-3047c595ab80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7bea-a35f-7d0a87a7e101" xlink:to="loc_us-gaap_SecuredDebtMember_019f8f48-41c0-7874-a7eb-3047c595ab80" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019f8f48-41c0-738e-8cf2-76186a7d6856" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7bea-a35f-7d0a87a7e101" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019f8f48-41c0-738e-8cf2-76186a7d6856" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-73b5-9fb1-9ce56fc6f894" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-74eb-9d26-0ad13a31dd17" xlink:to="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-73b5-9fb1-9ce56fc6f894" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-73b5-9fb1-9ce56fc6f894_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-73b5-9fb1-9ce56fc6f894" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-73b5-9fb1-9ce56fc6f894_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-73b5-9fb1-9ce56fc6f894" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A2025TermCreditAgreementAnd2025CreditAgreementMember_01a13f13-b234-716e-baf0-eea9a589ff51" xlink:href="wab-20260930.xsd#wab_A2025TermCreditAgreementAnd2025CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_A2025TermCreditAgreementAnd2025CreditAgreementMember_01a13f13-b234-716e-baf0-eea9a589ff51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A2025TermCreditAgreementMember_019f8f48-41c0-76c5-a46c-8fd9f9a0121e" xlink:href="wab-20260930.xsd#wab_A2025TermCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_A2025TermCreditAgreementAnd2025CreditAgreementMember_01a13f13-b234-716e-baf0-eea9a589ff51" xlink:to="loc_wab_A2025TermCreditAgreementMember_019f8f48-41c0-76c5-a46c-8fd9f9a0121e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A2025CreditAgreementMember_019f8f48-41c0-7417-bd27-ffedbdca537f" xlink:href="wab-20260930.xsd#wab_A2025CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_A2025TermCreditAgreementAnd2025CreditAgreementMember_01a13f13-b234-716e-baf0-eea9a589ff51" xlink:to="loc_wab_A2025CreditAgreementMember_019f8f48-41c0-7417-bd27-ffedbdca537f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RestatedCreditAgreementMember_019f8f48-41c0-71aa-94a2-3ff1712fcf2f" xlink:href="wab-20260930.xsd#wab_RestatedCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_RestatedCreditAgreementMember_019f8f48-41c0-71aa-94a2-3ff1712fcf2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_CommercialPaperProgramMember_01a116e0-fe48-7a99-acd4-3c5d549431e6" xlink:href="wab-20260930.xsd#wab_CommercialPaperProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_CommercialPaperProgramMember_01a116e0-fe48-7a99-acd4-3c5d549431e6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_019f8f48-41c0-7c5a-841c-334a89288a90" xlink:href="wab-20260930.xsd#wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_019f8f48-41c0-7c5a-841c-334a89288a90" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A125PercentEuroNotesDueTwoThousandAndTwentySevenMember_019f8f48-41c0-7cc9-b62a-77fc8be2d273" xlink:href="wab-20260930.xsd#wab_A125PercentEuroNotesDueTwoThousandAndTwentySevenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_A125PercentEuroNotesDueTwoThousandAndTwentySevenMember_019f8f48-41c0-7cc9-b62a-77fc8be2d273" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentyEightMember_019f8f48-41c0-7b6e-933e-2bed2c781a2c" xlink:href="wab-20260930.xsd#wab_A470PercentSeniorNotesDueTwoThousandAndTwentyEightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentyEightMember_019f8f48-41c0-7b6e-933e-2bed2c781a2c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4.90PercentSeniorNotesDueTwoThousandAndThirtyMember_019f8f48-41c0-7f5d-b3ee-6efeceb040b7" xlink:href="wab-20260930.xsd#wab_A4.90PercentSeniorNotesDueTwoThousandAndThirtyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_A4.90PercentSeniorNotesDueTwoThousandAndThirtyMember_019f8f48-41c0-7f5d-b3ee-6efeceb040b7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A5.611PercentSeniorNotesDueTwoThousandAndThirtyFourMember_019f8f48-41c0-7000-8bcd-9c27940bbcb8" xlink:href="wab-20260930.xsd#wab_A5.611PercentSeniorNotesDueTwoThousandAndThirtyFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_A5.611PercentSeniorNotesDueTwoThousandAndThirtyFourMember_019f8f48-41c0-7000-8bcd-9c27940bbcb8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A5.50PercentSeniorNotesDueTwoThousandAndThirtyFiveMember_019f8f48-41c0-779d-9108-4d19a18dd6e4" xlink:href="wab-20260930.xsd#wab_A5.50PercentSeniorNotesDueTwoThousandAndThirtyFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7bb1-8a6f-b0b030aef630" xlink:to="loc_wab_A5.50PercentSeniorNotesDueTwoThousandAndThirtyFiveMember_019f8f48-41c0-779d-9108-4d19a18dd6e4" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7440-b99c-473dd10821ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-74eb-9d26-0ad13a31dd17" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7440-b99c-473dd10821ca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7440-b99c-473dd10821ca_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7440-b99c-473dd10821ca" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7440-b99c-473dd10821ca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7ac2-9749-95a514106689" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-7440-b99c-473dd10821ca" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7ac2-9749-95a514106689" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019f8f48-41c0-7f87-8ccb-6a81f43422da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7ac2-9749-95a514106689" xlink:to="loc_us-gaap_LineOfCreditMember_019f8f48-41c0-7f87-8ccb-6a81f43422da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019f8f48-41c0-7117-bc6e-8f3fbd28407f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7ac2-9749-95a514106689" xlink:to="loc_us-gaap_SeniorNotesMember_019f8f48-41c0-7117-bc6e-8f3fbd28407f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_01a116e0-fe48-7c56-98b6-4c1727be94ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-74eb-9d26-0ad13a31dd17" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_01a116e0-fe48-7c56-98b6-4c1727be94ea" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_01a116e0-fe48-7c56-98b6-4c1727be94ea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_01a116e0-fe48-7c56-98b6-4c1727be94ea" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_01a116e0-fe48-7c56-98b6-4c1727be94ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_01a116e0-fe48-7a5a-8a4f-8f726488627a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_01a116e0-fe48-7c56-98b6-4c1727be94ea" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_01a116e0-fe48-7a5a-8a4f-8f726488627a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_01a116e0-fe48-755e-996f-2075d046c54e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_01a116e0-fe48-7a5a-8a4f-8f726488627a" xlink:to="loc_us-gaap_CommercialPaperMember_01a116e0-fe48-755e-996f-2075d046c54e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_01a12fd3-d920-7bdd-a692-e30aea55f2b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-74eb-9d26-0ad13a31dd17" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_01a12fd3-d920-7bdd-a692-e30aea55f2b1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a12fd3-d920-7bdd-a692-e30aea55f2b1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a12fd3-d920-7bdd-a692-e30aea55f2b1" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a12fd3-d920-7bdd-a692-e30aea55f2b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a12fd3-d920-76a6-b740-295f7aace1c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a12fd3-d920-7bdd-a692-e30aea55f2b1" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a12fd3-d920-76a6-b740-295f7aace1c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_01a12fd3-feda-7f2b-b713-1c355c713458" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_01a12fd3-d920-76a6-b740-295f7aace1c7" xlink:to="loc_us-gaap_SubsequentEventMember_01a12fd3-feda-7f2b-b713-1c355c713458" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019f8f48-41c0-79a0-9627-102e4bdf58e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019f8f48-41c0-79a0-9627-102e4bdf58e4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019f8f48-41c0-791b-a705-ae46fdab6f42" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019f8f48-41c0-791b-a705-ae46fdab6f42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration_019f8f48-41c0-7512-a166-a9730b27142c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration_019f8f48-41c0-7512-a166-a9730b27142c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019f8f48-41c0-7495-81a0-cdf7972cac62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019f8f48-41c0-7495-81a0-cdf7972cac62" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_019f8f48-41c0-7560-8d82-36e638e1765f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_019f8f48-41c0-7560-8d82-36e638e1765f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f8f48-41c0-7353-bab0-b56b414ed54a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f8f48-41c0-7353-bab0-b56b414ed54a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019f8f48-41c0-7c69-94fd-836cc3d99a52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019f8f48-41c0-7c69-94fd-836cc3d99a52" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantInterestCoverageRatioMinimum_019f8f48-41c0-7318-86b9-ce42296f352d" xlink:href="wab-20260930.xsd#wab_DebtInstrumentCovenantInterestCoverageRatioMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_wab_DebtInstrumentCovenantInterestCoverageRatioMinimum_019f8f48-41c0-7318-86b9-ce42296f352d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantLeverageRatioMaximum_019f8f48-41c0-7b63-a319-2ef5cbbe7dec" xlink:href="wab-20260930.xsd#wab_DebtInstrumentCovenantLeverageRatioMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_wab_DebtInstrumentCovenantLeverageRatioMaximum_019f8f48-41c0-7b63-a319-2ef5cbbe7dec" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantLeverageRatioCalculationRestrictedCashAmount_019f8f48-41c0-7b4f-8945-bf2db241111b" xlink:href="wab-20260930.xsd#wab_DebtInstrumentCovenantLeverageRatioCalculationRestrictedCashAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_wab_DebtInstrumentCovenantLeverageRatioCalculationRestrictedCashAmount_019f8f48-41c0-7b4f-8945-bf2db241111b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f8f48-41c0-7eea-bbe1-9bbec276e6ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f8f48-41c0-7eea-bbe1-9bbec276e6ff" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_019f8f48-41c0-767f-bc57-82d3b1e2c942" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_019f8f48-41c0-767f-bc57-82d3b1e2c942" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentIssuancePercentageOfFaceValue_019f8f48-41c0-7760-9046-84765ca4d94d" xlink:href="wab-20260930.xsd#wab_DebtInstrumentIssuancePercentageOfFaceValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_wab_DebtInstrumentIssuancePercentageOfFaceValue_019f8f48-41c0-7760-9046-84765ca4d94d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_019f8f48-41c0-762e-a3d1-1c89e50468d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-7fed-926d-a81ce48ee892" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_019f8f48-41c0-762e-a3d1-1c89e50468d2" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-720b-a88e-21d927d44e9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7531-99ec-b9eca9156b48" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-720b-a88e-21d927d44e9a" xlink:to="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7531-99ec-b9eca9156b48" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-792b-b329-4dd1dfde2285" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7531-99ec-b9eca9156b48" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-792b-b329-4dd1dfde2285" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-792b-b329-4dd1dfde2285_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-792b-b329-4dd1dfde2285" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-792b-b329-4dd1dfde2285_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7297-b7dc-71f8bff8f414" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8f48-41c0-792b-b329-4dd1dfde2285" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7297-b7dc-71f8bff8f414" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019f8f48-41c0-7641-a04d-f7cb83059600" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019f8f48-41c0-7297-b7dc-71f8bff8f414" xlink:to="loc_us-gaap_LineOfCreditMember_019f8f48-41c0-7641-a04d-f7cb83059600" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-73e6-bce1-ec68dd956106" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7531-99ec-b9eca9156b48" xlink:to="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-73e6-bce1-ec68dd956106" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-73e6-bce1-ec68dd956106_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-73e6-bce1-ec68dd956106" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-73e6-bce1-ec68dd956106_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7f58-ad88-611da6b03740" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8f48-41c0-73e6-bce1-ec68dd956106" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7f58-ad88-611da6b03740" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019f8f48-41c0-78e0-a8e3-f6b3865e4434" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7f58-ad88-611da6b03740" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019f8f48-41c0-78e0-a8e3-f6b3865e4434" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019f8f48-41c0-7e40-8285-b9cf9f7cf020" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019f8f48-41c0-7f58-ad88-611da6b03740" xlink:to="loc_us-gaap_SecuredDebtMember_019f8f48-41c0-7e40-8285-b9cf9f7cf020" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7432-bd69-567e82ab0126" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8f48-41c0-7531-99ec-b9eca9156b48" xlink:to="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7432-bd69-567e82ab0126" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7432-bd69-567e82ab0126_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7432-bd69-567e82ab0126" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7432-bd69-567e82ab0126_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7d8f-903c-b63c076105e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8f48-41c0-7432-bd69-567e82ab0126" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7d8f-903c-b63c076105e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_019f8f48-41c0-70ec-a1b3-13d8fbc709e0" xlink:href="wab-20260930.xsd#wab_TwoThousandandEighteenRefinancingAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7d8f-903c-b63c076105e2" xlink:to="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_019f8f48-41c0-70ec-a1b3-13d8fbc709e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RestatedCreditAgreementMember_019f8f48-41c0-73b5-be9c-a5602ea42b4b" xlink:href="wab-20260930.xsd#wab_RestatedCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8f48-41c0-7d8f-903c-b63c076105e2" xlink:to="loc_wab_RestatedCreditAgreementMember_019f8f48-41c0-73b5-be9c-a5602ea42b4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f8f48-41c0-780f-8759-cc913176360a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-720b-a88e-21d927d44e9a" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f8f48-41c0-780f-8759-cc913176360a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019f8f48-41c0-7b38-b580-117e66b5cadc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-720b-a88e-21d927d44e9a" xlink:to="loc_us-gaap_LineOfCredit_019f8f48-41c0-7b38-b580-117e66b5cadc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019f8f48-41c0-7ee0-9148-6576d5ea6a18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-720b-a88e-21d927d44e9a" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019f8f48-41c0-7ee0-9148-6576d5ea6a18" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019f8f48-41c0-7790-a8ff-e7a9529c0fb6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8f48-41c0-720b-a88e-21d927d44e9a" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019f8f48-41c0-7790-a8ff-e7a9529c0fb6" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/STOCKBASEDCOMPENSATIONAdditionalInformationDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#STOCKBASEDCOMPENSATIONAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/STOCKBASEDCOMPENSATIONAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7ed7-b45c-22833d86618a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7ed7-b45c-22833d86618a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019f8f48-41c0-762a-917a-e0d5bf970292" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7ed7-b45c-22833d86618a" xlink:to="loc_us-gaap_PlanNameAxis_019f8f48-41c0-762a-917a-e0d5bf970292" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f8f48-41c0-762a-917a-e0d5bf970292_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_019f8f48-41c0-762a-917a-e0d5bf970292" xlink:to="loc_us-gaap_PlanNameDomain_019f8f48-41c0-762a-917a-e0d5bf970292_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f8f48-41c0-7373-b578-cc6c5622d063" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_019f8f48-41c0-762a-917a-e0d5bf970292" xlink:to="loc_us-gaap_PlanNameDomain_019f8f48-41c0-7373-b578-cc6c5622d063" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PlanTwoThousandElevenAndTwoThousandMember_019f8f48-41c0-78eb-a9dc-3cee31cd76f6" xlink:href="wab-20260930.xsd#wab_PlanTwoThousandElevenAndTwoThousandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019f8f48-41c0-7373-b578-cc6c5622d063" xlink:to="loc_wab_PlanTwoThousandElevenAndTwoThousandMember_019f8f48-41c0-78eb-a9dc-3cee31cd76f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PlanTwoThousandElevenMember_019f8f48-41c0-73b6-899c-2e1e0ba9d6c1" xlink:href="wab-20260930.xsd#wab_PlanTwoThousandElevenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_PlanTwoThousandElevenAndTwoThousandMember_019f8f48-41c0-78eb-a9dc-3cee31cd76f6" xlink:to="loc_wab_PlanTwoThousandElevenMember_019f8f48-41c0-73b6-899c-2e1e0ba9d6c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DirectorsPlanMember_019f8f48-41c0-7f94-a19a-4f3e2f335db0" xlink:href="wab-20260930.xsd#wab_DirectorsPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019f8f48-41c0-7373-b578-cc6c5622d063" xlink:to="loc_wab_DirectorsPlanMember_019f8f48-41c0-7f94-a19a-4f3e2f335db0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A2026PerformanceGoalPlanMember_019f8f48-41c0-731b-8286-f6ccd888cd05" xlink:href="wab-20260930.xsd#wab_A2026PerformanceGoalPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_019f8f48-41c0-7373-b578-cc6c5622d063" xlink:to="loc_wab_A2026PerformanceGoalPlanMember_019f8f48-41c0-731b-8286-f6ccd888cd05" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-71c9-b5ef-671ba7fe7789" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7ed7-b45c-22833d86618a" xlink:to="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-71c9-b5ef-671ba7fe7789" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-71c9-b5ef-671ba7fe7789_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-71c9-b5ef-671ba7fe7789" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-71c9-b5ef-671ba7fe7789_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7465-aa9d-4889b41f4972" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-71c9-b5ef-671ba7fe7789" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7465-aa9d-4889b41f4972" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019f8f48-41c0-75cd-9f7f-95f4cf761325" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7465-aa9d-4889b41f4972" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019f8f48-41c0-75cd-9f7f-95f4cf761325" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f8f48-41c0-73d8-b2c9-0a218759d8b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7465-aa9d-4889b41f4972" xlink:to="loc_us-gaap_RestrictedStockMember_019f8f48-41c0-73d8-b2c9-0a218759d8b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019f8f48-41c0-78a7-8995-4e44d04dbd04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7465-aa9d-4889b41f4972" xlink:to="loc_us-gaap_PerformanceSharesMember_019f8f48-41c0-78a7-8995-4e44d04dbd04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f8f48-41c0-7e34-91f5-fef7e2bea904" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7ed7-b45c-22833d86618a" xlink:to="loc_srt_RangeAxis_019f8f48-41c0-7e34-91f5-fef7e2bea904" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8f48-41c0-7e34-91f5-fef7e2bea904_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019f8f48-41c0-7e34-91f5-fef7e2bea904" xlink:to="loc_srt_RangeMember_019f8f48-41c0-7e34-91f5-fef7e2bea904_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8f48-41c0-75c5-8ab0-d28fa8c96029" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019f8f48-41c0-7e34-91f5-fef7e2bea904" xlink:to="loc_srt_RangeMember_019f8f48-41c0-75c5-8ab0-d28fa8c96029" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f8f48-41c0-7592-ba9e-666e29288891" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8f48-41c0-75c5-8ab0-d28fa8c96029" xlink:to="loc_srt_MinimumMember_019f8f48-41c0-7592-ba9e-666e29288891" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f8f48-41c0-7e51-b95f-adb40aa5eb7f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8f48-41c0-75c5-8ab0-d28fa8c96029" xlink:to="loc_srt_MaximumMember_019f8f48-41c0-7e51-b95f-adb40aa5eb7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_019f8f48-41c0-761d-b559-b8decff70b46" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7ed7-b45c-22833d86618a" xlink:to="loc_srt_StatementScenarioAxis_019f8f48-41c0-761d-b559-b8decff70b46" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019f8f48-41c0-761d-b559-b8decff70b46_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_019f8f48-41c0-761d-b559-b8decff70b46" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019f8f48-41c0-761d-b559-b8decff70b46_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019f8f48-41c0-735a-bbfe-9ab17d0a70cc" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_019f8f48-41c0-761d-b559-b8decff70b46" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019f8f48-41c0-735a-bbfe-9ab17d0a70cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_019f8f48-41c0-70b1-814c-61479aa78753" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_019f8f48-41c0-735a-bbfe-9ab17d0a70cc" xlink:to="loc_srt_ScenarioForecastMember_019f8f48-41c0-70b1-814c-61479aa78753" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_019f8f48-41c0-7dcf-acbf-584c83fda30a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_019f8f48-41c0-7dcf-acbf-584c83fda30a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f8f48-41c0-79cd-a0cc-ff1e6e946098" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f8f48-41c0-79cd-a0cc-ff1e6e946098" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019f8f48-41c0-7e6f-b8d7-da452c03b4ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_019f8f48-41c0-7e6f-b8d7-da452c03b4ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019f8f48-41c0-7bd4-8ce8-88b380b3967f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019f8f48-41c0-7bd4-8ce8-88b380b3967f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019f8f48-41c0-746c-9475-f44b88a8ceba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019f8f48-41c0-746c-9475-f44b88a8ceba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_019f8f48-41c0-73e5-b945-9707c512410d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_019f8f48-41c0-73e5-b945-9707c512410d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_019f8f48-41c0-7578-9165-98060b14e83f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_019f8f48-41c0-7578-9165-98060b14e83f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_019f8f48-41c0-7c9f-9ad1-4c4071b37bce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_019f8f48-41c0-7c9f-9ad1-4c4071b37bce" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationRelativeTotalStockholderReturnModifierPaymentPercentageIncrease_019f8f48-41c0-7c1a-8170-64226ae3dffd" xlink:href="wab-20260930.xsd#wab_ShareBasedCompensationRelativeTotalStockholderReturnModifierPaymentPercentageIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_wab_ShareBasedCompensationRelativeTotalStockholderReturnModifierPaymentPercentageIncrease_019f8f48-41c0-7c1a-8170-64226ae3dffd" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationRelativeTotalStockholderReturnModifierPaymentPercentageDecrease_019f8f48-41c0-70d9-b115-4501a0cad883" xlink:href="wab-20260930.xsd#wab_ShareBasedCompensationRelativeTotalStockholderReturnModifierPaymentPercentageDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_wab_ShareBasedCompensationRelativeTotalStockholderReturnModifierPaymentPercentageDecrease_019f8f48-41c0-70d9-b115-4501a0cad883" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019f8f48-41c0-73d2-9f11-4bb4e7d8506d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7b94-a32b-08aeb80e9974" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_019f8f48-41c0-73d2-9f11-4bb4e7d8506d" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/STOCKBASEDCOMPENSATIONScheduleofRestrictedStockActivityandIncentiveStockAwardsActivityDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#STOCKBASEDCOMPENSATIONScheduleofRestrictedStockActivityandIncentiveStockAwardsActivityDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/STOCKBASEDCOMPENSATIONScheduleofRestrictedStockActivityandIncentiveStockAwardsActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7936-84d1-4c86fc2b7a56" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7012-a2ac-8f5ec402e575" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7936-84d1-4c86fc2b7a56" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7012-a2ac-8f5ec402e575" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7567-b153-e8c00ff42cbb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8f48-41c0-7012-a2ac-8f5ec402e575" xlink:to="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7567-b153-e8c00ff42cbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7567-b153-e8c00ff42cbb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7567-b153-e8c00ff42cbb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7567-b153-e8c00ff42cbb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7985-bc64-ca8a65fdb9f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7567-b153-e8c00ff42cbb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7985-bc64-ca8a65fdb9f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RestrictedStockAndUnitsMember_019f8f48-41c0-70af-a049-941146a15e4c" xlink:href="wab-20260930.xsd#wab_RestrictedStockAndUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7985-bc64-ca8a65fdb9f9" xlink:to="loc_wab_RestrictedStockAndUnitsMember_019f8f48-41c0-70af-a049-941146a15e4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019f8f48-41c0-7d50-b200-2fde451c31a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7985-bc64-ca8a65fdb9f9" xlink:to="loc_us-gaap_PerformanceSharesMember_019f8f48-41c0-7d50-b200-2fde451c31a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f8f48-41c0-7518-8c0f-8c291eeab47c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7936-84d1-4c86fc2b7a56" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f8f48-41c0-7518-8c0f-8c291eeab47c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f8f48-41c0-7145-acba-52e09874642d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f8f48-41c0-7518-8c0f-8c291eeab47c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f8f48-41c0-7145-acba-52e09874642d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f8f48-41c0-7500-8574-2fdb8c36b38b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f8f48-41c0-7518-8c0f-8c291eeab47c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f8f48-41c0-7500-8574-2fdb8c36b38b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f8f48-41c0-743a-9535-0e3dda775dbb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f8f48-41c0-7518-8c0f-8c291eeab47c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f8f48-41c0-743a-9535-0e3dda775dbb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest_019f8f48-41c0-7037-967d-f9d43ff54f11" xlink:href="wab-20260930.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f8f48-41c0-7518-8c0f-8c291eeab47c" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest_019f8f48-41c0-7037-967d-f9d43ff54f11" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f8f48-41c0-74ef-a839-deffd885188e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f8f48-41c0-7518-8c0f-8c291eeab47c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f8f48-41c0-74ef-a839-deffd885188e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f8f48-41c0-75b2-867b-0d4c8a839004" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f8f48-41c0-7915-8a04-8cdce4f9d6e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8f48-41c0-7936-84d1-4c86fc2b7a56" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f8f48-41c0-7915-8a04-8cdce4f9d6e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f8f48-41c0-7750-b6ad-976d0de54ccc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f8f48-41c0-7915-8a04-8cdce4f9d6e4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f8f48-41c0-7750-b6ad-976d0de54ccc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f8f48-41c0-796f-a59f-989bd9bfceb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f8f48-41c0-7915-8a04-8cdce4f9d6e4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f8f48-41c0-796f-a59f-989bd9bfceb8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f8f48-41c0-7b72-8a44-1f32ccea2e4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f8f48-41c0-7915-8a04-8cdce4f9d6e4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f8f48-41c0-7b72-8a44-1f32ccea2e4d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue_019f8f48-41c0-7329-9576-81ae9ed11c2d" xlink:href="wab-20260930.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f8f48-41c0-7915-8a04-8cdce4f9d6e4" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue_019f8f48-41c0-7329-9576-81ae9ed11c2d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f8f48-41c0-779c-84ab-078b43326cb0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_019f8f48-41c0-7915-8a04-8cdce4f9d6e4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f8f48-41c0-779c-84ab-078b43326cb0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f8f48-41c0-7ebb-8b69-11241805f541" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/EARNINGSPERSHAREScheduleofComputationofEarningsPerShareDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#EARNINGSPERSHAREScheduleofComputationofEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/EARNINGSPERSHAREScheduleofComputationofEarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedLineItems_019f8f48-41c0-7f75-a4ac-87232a671dc4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDilutedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_019f8f48-41c0-7b82-a7c1-25873bf4e5e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_019f8f48-41c0-7f75-a4ac-87232a671dc4" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_019f8f48-41c0-7b82-a7c1-25873bf4e5e6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7618-b13c-7f3434f7e7ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_019f8f48-41c0-7b82-a7c1-25873bf4e5e6" xlink:to="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7618-b13c-7f3434f7e7ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7618-b13c-7f3434f7e7ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7618-b13c-7f3434f7e7ce" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-7618-b13c-7f3434f7e7ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-708b-9d1e-904a79195997" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019f8f48-41c0-7618-b13c-7f3434f7e7ce" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-708b-9d1e-904a79195997" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AwardsExcludingRestrictedStockMember_019f8f48-41c0-7838-a1fc-448078ebc940" xlink:href="wab-20260930.xsd#wab_AwardsExcludingRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-708b-9d1e-904a79195997" xlink:to="loc_wab_AwardsExcludingRestrictedStockMember_019f8f48-41c0-7838-a1fc-448078ebc940" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f8f48-41c0-76d3-bdd2-c76a6de5dfdc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8f48-41c0-708b-9d1e-904a79195997" xlink:to="loc_us-gaap_RestrictedStockMember_019f8f48-41c0-76d3-bdd2-c76a6de5dfdc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAbstract_019f8f48-41c0-710c-837c-b89b2185fdbe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_019f8f48-41c0-7f75-a4ac-87232a671dc4" xlink:to="loc_us-gaap_NetIncomeLossAbstract_019f8f48-41c0-710c-837c-b89b2185fdbe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f8f48-41c0-7411-b840-2d0f35a25e1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_019f8f48-41c0-710c-837c-b89b2185fdbe" xlink:to="loc_us-gaap_NetIncomeLoss_019f8f48-41c0-7411-b840-2d0f35a25e1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAllocatedToGeneralPartners_019f8f48-41c0-7e5b-a32b-e7abcd2808f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAllocatedToGeneralPartners"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_019f8f48-41c0-710c-837c-b89b2185fdbe" xlink:to="loc_us-gaap_NetIncomeLossAllocatedToGeneralPartners_019f8f48-41c0-7e5b-a32b-e7abcd2808f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019f8f48-41c0-754d-b4b1-3daefd8138dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_019f8f48-41c0-710c-837c-b89b2185fdbe" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019f8f48-41c0-754d-b4b1-3daefd8138dd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019f8f48-41c0-7a13-afe1-f70058c2dc58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetIncomeLossAbstract_019f8f48-41c0-710c-837c-b89b2185fdbe" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019f8f48-41c0-7a13-afe1-f70058c2dc58" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019f8f48-41c0-7f0d-a805-7b671f92d706" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_019f8f48-41c0-7f75-a4ac-87232a671dc4" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019f8f48-41c0-7f0d-a805-7b671f92d706" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f8f48-41c0-782f-bc8e-069300c6ea99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019f8f48-41c0-7f0d-a805-7b671f92d706" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019f8f48-41c0-782f-bc8e-069300c6ea99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019f8f48-41c0-7a2d-b206-8cb6322f9ba9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019f8f48-41c0-7f0d-a805-7b671f92d706" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019f8f48-41c0-7a2d-b206-8cb6322f9ba9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f8f48-41c0-7925-95fb-5f36cc231540" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_019f8f48-41c0-7f0d-a805-7b671f92d706" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019f8f48-41c0-7925-95fb-5f36cc231540" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_EarningsPerShareBasicAndDilutedEPSAbstract_019f8f48-41c0-74eb-9e7a-ae4db161fead" xlink:href="wab-20260930.xsd#wab_EarningsPerShareBasicAndDilutedEPSAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_019f8f48-41c0-7f75-a4ac-87232a671dc4" xlink:to="loc_wab_EarningsPerShareBasicAndDilutedEPSAbstract_019f8f48-41c0-74eb-9e7a-ae4db161fead" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019f8f48-41c0-7af0-9714-3b75baae9c24" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_EarningsPerShareBasicAndDilutedEPSAbstract_019f8f48-41c0-74eb-9e7a-ae4db161fead" xlink:to="loc_us-gaap_EarningsPerShareBasic_019f8f48-41c0-7af0-9714-3b75baae9c24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019f8f48-41c0-7e51-a5c4-44ea9917ac9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_EarningsPerShareBasicAndDilutedEPSAbstract_019f8f48-41c0-74eb-9e7a-ae4db161fead" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019f8f48-41c0-7e51-a5c4-44ea9917ac9a" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-72ba-807b-ac6bfce45e2f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_019f8f48-41c0-7b35-910c-245d2548d3e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-72ba-807b-ac6bfce45e2f" xlink:to="loc_us-gaap_DerivativeTable_019f8f48-41c0-7b35-910c-245d2548d3e5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7635-9385-5d7ad7fdd329" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019f8f48-41c0-7b35-910c-245d2548d3e5" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7635-9385-5d7ad7fdd329" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7635-9385-5d7ad7fdd329_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7635-9385-5d7ad7fdd329" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7635-9385-5d7ad7fdd329_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-76a5-9bee-1cf841632a20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7635-9385-5d7ad7fdd329" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-76a5-9bee-1cf841632a20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FrauscherAcquisitionAndAgreementToAcquireDellnerCouplersMember_019f8f48-41c0-7592-aca2-06ff47430271" xlink:href="wab-20260930.xsd#wab_FrauscherAcquisitionAndAgreementToAcquireDellnerCouplersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-76a5-9bee-1cf841632a20" xlink:to="loc_wab_FrauscherAcquisitionAndAgreementToAcquireDellnerCouplersMember_019f8f48-41c0-7592-aca2-06ff47430271" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-7d96-a858-3cbe8af0356e" xlink:href="wab-20260930.xsd#wab_FrauscherSensorTechnologyGroupGmbHMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-76a5-9bee-1cf841632a20" xlink:to="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-7d96-a858-3cbe8af0356e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DellnerCouplersMember_019f8f48-41c0-7667-a3b9-e2419e318520" xlink:href="wab-20260930.xsd#wab_DellnerCouplersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-76a5-9bee-1cf841632a20" xlink:to="loc_wab_DellnerCouplersMember_019f8f48-41c0-7667-a3b9-e2419e318520" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7cb3-8ff2-5077f07f508e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019f8f48-41c0-7b35-910c-245d2548d3e5" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7cb3-8ff2-5077f07f508e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-7cb3-8ff2-5077f07f508e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7cb3-8ff2-5077f07f508e" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-7cb3-8ff2-5077f07f508e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-7e0b-b270-74c39aa01002" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7cb3-8ff2-5077f07f508e" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-7e0b-b270-74c39aa01002" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_019f8f48-41c0-7c32-ab6f-ff55931db367" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-7e0b-b270-74c39aa01002" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_019f8f48-41c0-7c32-ab6f-ff55931db367" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7408-a47c-3de51594816b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019f8f48-41c0-7b35-910c-245d2548d3e5" xlink:to="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7408-a47c-3de51594816b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-7408-a47c-3de51594816b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7408-a47c-3de51594816b" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-7408-a47c-3de51594816b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-75a1-87ce-c812b42a1fff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7408-a47c-3de51594816b" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-75a1-87ce-c812b42a1fff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019f8f48-41c0-7fe5-8946-24728ce42e05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-75a1-87ce-c812b42a1fff" xlink:to="loc_us-gaap_NondesignatedMember_019f8f48-41c0-7fe5-8946-24728ce42e05" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f8f48-41c0-70a2-aede-89397d25fb61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-75a1-87ce-c812b42a1fff" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f8f48-41c0-70a2-aede-89397d25fb61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019f8f48-41c0-77cc-9bc9-8dc68d56a8eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-72ba-807b-ac6bfce45e2f" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019f8f48-41c0-77cc-9bc9-8dc68d56a8eb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019f8f48-41c0-7d00-aded-56ef32601aac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-72ba-807b-ac6bfce45e2f" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019f8f48-41c0-7d00-aded-56ef32601aac" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/SEGMENTINFORMATIONScheduleofSegmentFinancialInformationDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#SEGMENTINFORMATIONScheduleofSegmentFinancialInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/SEGMENTINFORMATIONScheduleofSegmentFinancialInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7916-9b6d-6887f7581743" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7916-9b6d-6887f7581743" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-723c-86bd-b7f1307a2f83" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7916-9b6d-6887f7581743" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-723c-86bd-b7f1307a2f83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-723c-86bd-b7f1307a2f83_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-723c-86bd-b7f1307a2f83" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-723c-86bd-b7f1307a2f83_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-7ddd-a2e3-3c2442520913" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-723c-86bd-b7f1307a2f83" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-7ddd-a2e3-3c2442520913" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_019f8f48-41c0-7d9d-bba8-2e30dc3268d8" xlink:href="wab-20260930.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7ddd-a2e3-3c2442520913" xlink:to="loc_wab_FreightSegmentMember_019f8f48-41c0-7d9d-bba8-2e30dc3268d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_019f8f48-41c0-762e-82ef-f3d0d0bf29b9" xlink:href="wab-20260930.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7ddd-a2e3-3c2442520913" xlink:to="loc_wab_TransitSegmentMember_019f8f48-41c0-762e-82ef-f3d0d0bf29b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-73d0-982d-89ec4dce577c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7916-9b6d-6887f7581743" xlink:to="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-73d0-982d-89ec4dce577c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-73d0-982d-89ec4dce577c_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-73d0-982d-89ec4dce577c" xlink:to="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-73d0-982d-89ec4dce577c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7704-bbcb-29260c979316" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-73d0-982d-89ec4dce577c" xlink:to="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7704-bbcb-29260c979316" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f8f48-41c0-7109-b21f-5488f807889f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7704-bbcb-29260c979316" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f8f48-41c0-7109-b21f-5488f807889f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019f8f48-41c0-71c0-bf1f-5bca02b40b85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7704-bbcb-29260c979316" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019f8f48-41c0-71c0-bf1f-5bca02b40b85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019f8f48-41c0-7ca6-a4d2-edf5a8f1b072" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7704-bbcb-29260c979316" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019f8f48-41c0-7ca6-a4d2-edf5a8f1b072" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f8f48-41c0-757f-bb3b-77140eb80367" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f8f48-41c0-757f-bb3b-77140eb80367" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019f8f48-41c0-790e-8a7a-df569de1501c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019f8f48-41c0-790e-8a7a-df569de1501c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019f8f48-41c0-7eeb-91d8-a656bb01f637" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSold_019f8f48-41c0-790e-8a7a-df569de1501c" xlink:to="loc_us-gaap_GrossProfit_019f8f48-41c0-7eeb-91d8-a656bb01f637" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GrossMarginPercent_019f8f48-41c0-718c-aea1-abfde40c085b" xlink:href="wab-20260930.xsd#wab_GrossMarginPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSold_019f8f48-41c0-790e-8a7a-df569de1501c" xlink:to="loc_wab_GrossMarginPercent_019f8f48-41c0-718c-aea1-abfde40c085b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019f8f48-41c0-72e8-8e14-8db92671198e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019f8f48-41c0-72e8-8e14-8db92671198e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019f8f48-41c0-7853-93ed-b756fba71812" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019f8f48-41c0-7853-93ed-b756fba71812" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019f8f48-41c0-7eb5-8d66-7572effaf8af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019f8f48-41c0-7eb5-8d66-7572effaf8af" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019f8f48-41c0-7439-aa43-a393f415b41f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_OperatingIncomeLoss_019f8f48-41c0-7439-aa43-a393f415b41f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_InterestExpenseAndOtherNet_019f8f48-41c0-78fa-8207-444fa91ee229" xlink:href="wab-20260930.xsd#wab_InterestExpenseAndOtherNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_wab_InterestExpenseAndOtherNet_019f8f48-41c0-78fa-8207-444fa91ee229" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f8f48-41c0-7ba3-908c-7399dee85719" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f8f48-41c0-7ba3-908c-7399dee85719" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019f8f48-41c0-7561-9a39-0f37cef82991" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_DepreciationAndAmortization_019f8f48-41c0-7561-9a39-0f37cef82991" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019f8f48-41c0-7ac2-8dd8-2e9f65e01635" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentExpenditureAdditionToLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019f8f48-41c0-7ac2-8dd8-2e9f65e01635" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019f8f48-41c0-78cb-81e3-1f2fdac04a0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-72d5-90c1-b7aa147c8035" xlink:to="loc_us-gaap_Assets_019f8f48-41c0-78cb-81e3-1f2fdac04a0a" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/SEGMENTINFORMATIONScheduleofSalesbyProductDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#SEGMENTINFORMATIONScheduleofSalesbyProductDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/SEGMENTINFORMATIONScheduleofSalesbyProductDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-7a00-8c0f-99e8fef5e5ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7864-aa76-3fb29dca4493" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-7a00-8c0f-99e8fef5e5ce" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7864-aa76-3fb29dca4493" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f8f48-41c0-769e-91b7-568964889e4e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7864-aa76-3fb29dca4493" xlink:to="loc_srt_ProductOrServiceAxis_019f8f48-41c0-769e-91b7-568964889e4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-769e-91b7-568964889e4e_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f8f48-41c0-769e-91b7-568964889e4e" xlink:to="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-769e-91b7-568964889e4e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f8f48-41c0-769e-91b7-568964889e4e" xlink:to="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019f8f48-41c0-7fb7-b861-ed2f2ff99320" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:to="loc_us-gaap_ServiceMember_019f8f48-41c0-7fb7-b861-ed2f2ff99320" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentMember_019f8f48-41c0-775e-be26-464b937ffaf8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:to="loc_us-gaap_EquipmentMember_019f8f48-41c0-775e-be26-464b937ffaf8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ComponentsMember_019f8f48-41c0-725b-866f-0f9205e804a5" xlink:href="wab-20260930.xsd#wab_ComponentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:to="loc_wab_ComponentsMember_019f8f48-41c0-725b-866f-0f9205e804a5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DigitalIntelligenceMember_019f8f48-41c0-7643-b5aa-e61807f4d243" xlink:href="wab-20260930.xsd#wab_DigitalIntelligenceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:to="loc_wab_DigitalIntelligenceMember_019f8f48-41c0-7643-b5aa-e61807f4d243" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OEMMember_019f8f48-41c0-725c-8fe3-b1f708b88b9d" xlink:href="wab-20260930.xsd#wab_OEMMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:to="loc_wab_OEMMember_019f8f48-41c0-725c-8fe3-b1f708b88b9d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AftermarketMember_019f8f48-41c0-7792-825a-3962a405b1d7" xlink:href="wab-20260930.xsd#wab_AftermarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8f48-41c0-747d-bed1-f7965991bdb6" xlink:to="loc_wab_AftermarketMember_019f8f48-41c0-7792-825a-3962a405b1d7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-728d-9a80-254003d99e09" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8f48-41c0-7864-aa76-3fb29dca4493" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-728d-9a80-254003d99e09" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-728d-9a80-254003d99e09_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-728d-9a80-254003d99e09" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-728d-9a80-254003d99e09_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-7cfb-800e-5aa8c25ead05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-728d-9a80-254003d99e09" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-7cfb-800e-5aa8c25ead05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_019f8f48-41c0-7b31-845c-c5794149f95e" xlink:href="wab-20260930.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7cfb-800e-5aa8c25ead05" xlink:to="loc_wab_FreightSegmentMember_019f8f48-41c0-7b31-845c-c5794149f95e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_019f8f48-41c0-7669-b00b-e906a13e47a6" xlink:href="wab-20260930.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7cfb-800e-5aa8c25ead05" xlink:to="loc_wab_TransitSegmentMember_019f8f48-41c0-7669-b00b-e906a13e47a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f8f48-41c0-70dd-8264-4a8a2c6fe18d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8f48-41c0-7a00-8c0f-99e8fef5e5ce" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f8f48-41c0-70dd-8264-4a8a2c6fe18d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/OTHERINCOMEEXPENSENETAdditionalInformationDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#OTHERINCOMEEXPENSENETAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/OTHERINCOMEEXPENSENETAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-75a2-b696-fe745ea591a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_019f8f48-41c0-782b-a3f6-713cfee9b69a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-75a2-b696-fe745ea591a0" xlink:to="loc_us-gaap_DerivativeTable_019f8f48-41c0-782b-a3f6-713cfee9b69a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7ebf-8c9f-63bc77509147" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019f8f48-41c0-782b-a3f6-713cfee9b69a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7ebf-8c9f-63bc77509147" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7ebf-8c9f-63bc77509147_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7ebf-8c9f-63bc77509147" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7ebf-8c9f-63bc77509147_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7c57-ad69-4958272b8e7d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8f48-41c0-7ebf-8c9f-63bc77509147" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7c57-ad69-4958272b8e7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FrauscherAcquisitionAndAgreementToAcquireDellnerCouplersMember_019f8f48-41c0-7502-9ee2-68432828b3ca" xlink:href="wab-20260930.xsd#wab_FrauscherAcquisitionAndAgreementToAcquireDellnerCouplersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7c57-ad69-4958272b8e7d" xlink:to="loc_wab_FrauscherAcquisitionAndAgreementToAcquireDellnerCouplersMember_019f8f48-41c0-7502-9ee2-68432828b3ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-75a5-8ab1-635a1ac9f259" xlink:href="wab-20260930.xsd#wab_FrauscherSensorTechnologyGroupGmbHMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7c57-ad69-4958272b8e7d" xlink:to="loc_wab_FrauscherSensorTechnologyGroupGmbHMember_019f8f48-41c0-75a5-8ab1-635a1ac9f259" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DellnerCouplersMember_019f8f48-41c0-72a3-a0e5-bdf7ec18322e" xlink:href="wab-20260930.xsd#wab_DellnerCouplersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8f48-41c0-7c57-ad69-4958272b8e7d" xlink:to="loc_wab_DellnerCouplersMember_019f8f48-41c0-72a3-a0e5-bdf7ec18322e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7086-a1b1-41bcccd6c787" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019f8f48-41c0-782b-a3f6-713cfee9b69a" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7086-a1b1-41bcccd6c787" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-7086-a1b1-41bcccd6c787_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7086-a1b1-41bcccd6c787" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-7086-a1b1-41bcccd6c787_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-702e-9c2c-6f004591d299" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8f48-41c0-7086-a1b1-41bcccd6c787" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-702e-9c2c-6f004591d299" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_019f8f48-41c0-76d5-bb84-c93c4b59a710" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019f8f48-41c0-702e-9c2c-6f004591d299" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_019f8f48-41c0-76d5-bb84-c93c4b59a710" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7b9a-a39b-53ae330495d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_019f8f48-41c0-782b-a3f6-713cfee9b69a" xlink:to="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7b9a-a39b-53ae330495d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-7b9a-a39b-53ae330495d9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7b9a-a39b-53ae330495d9" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-7b9a-a39b-53ae330495d9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-7825-adbb-061bb43eb7ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f8f48-41c0-7b9a-a39b-53ae330495d9" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-7825-adbb-061bb43eb7ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019f8f48-41c0-7ca1-9bc4-d5d6c7e6dd27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019f8f48-41c0-7825-adbb-061bb43eb7ae" xlink:to="loc_us-gaap_NondesignatedMember_019f8f48-41c0-7ca1-9bc4-d5d6c7e6dd27" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019f8f48-41c0-7b82-93c5-fa4a86776d6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-75a2-b696-fe745ea591a0" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019f8f48-41c0-7b82-93c5-fa4a86776d6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019f8f48-41c0-7662-a8f7-755defc159d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019f8f48-41c0-75a2-b696-fe745ea591a0" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019f8f48-41c0-7662-a8f7-755defc159d0" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/RESTRUCTURINGAdditionalInformationDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#RESTRUCTURINGAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/RESTRUCTURINGAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7d11-a096-f664faf4aeae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-72bb-b1fa-7413c75fb977" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7d11-a096-f664faf4aeae" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-72bb-b1fa-7413c75fb977" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f8f48-41c0-7d8d-8fad-efc8abb9f18e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-72bb-b1fa-7413c75fb977" xlink:to="loc_srt_RangeAxis_019f8f48-41c0-7d8d-8fad-efc8abb9f18e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8f48-41c0-7d8d-8fad-efc8abb9f18e_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019f8f48-41c0-7d8d-8fad-efc8abb9f18e" xlink:to="loc_srt_RangeMember_019f8f48-41c0-7d8d-8fad-efc8abb9f18e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8f48-41c0-7bdc-9644-8197e16a1539" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019f8f48-41c0-7d8d-8fad-efc8abb9f18e" xlink:to="loc_srt_RangeMember_019f8f48-41c0-7bdc-9644-8197e16a1539" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f8f48-41c0-7b28-bae0-2c838349c8fc" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8f48-41c0-7bdc-9644-8197e16a1539" xlink:to="loc_srt_MinimumMember_019f8f48-41c0-7b28-bae0-2c838349c8fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f8f48-41c0-74e5-b62a-f5e20f259d74" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8f48-41c0-7bdc-9644-8197e16a1539" xlink:to="loc_srt_MaximumMember_019f8f48-41c0-74e5-b62a-f5e20f259d74" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7935-9612-55f6a03ae4ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-72bb-b1fa-7413c75fb977" xlink:to="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7935-9612-55f6a03ae4ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7935-9612-55f6a03ae4ee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7935-9612-55f6a03ae4ee" xlink:to="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7935-9612-55f6a03ae4ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7989-8930-c812f9c2d43c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7935-9612-55f6a03ae4ee" xlink:to="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7989-8930-c812f9c2d43c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_Integration3.0Member_019f8f48-41c0-7d70-8b37-2e6865ed708b" xlink:href="wab-20260930.xsd#wab_Integration3.0Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7989-8930-c812f9c2d43c" xlink:to="loc_wab_Integration3.0Member_019f8f48-41c0-7d70-8b37-2e6865ed708b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PortfolioOptimizationMember_019f8f48-41c0-7681-accd-f52f0fd06f60" xlink:href="wab-20260930.xsd#wab_PortfolioOptimizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7989-8930-c812f9c2d43c" xlink:to="loc_wab_PortfolioOptimizationMember_019f8f48-41c0-7681-accd-f52f0fd06f60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_Integration20Member_019f8f48-41c0-77a2-94b2-e38ebe9b4b12" xlink:href="wab-20260930.xsd#wab_Integration20Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7989-8930-c812f9c2d43c" xlink:to="loc_wab_Integration20Member_019f8f48-41c0-77a2-94b2-e38ebe9b4b12" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_019f8f48-41c0-7afe-8c2f-ed17446c1e92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-72bb-b1fa-7413c75fb977" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_019f8f48-41c0-7afe-8c2f-ed17446c1e92" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_019f8f48-41c0-7afe-8c2f-ed17446c1e92_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_019f8f48-41c0-7afe-8c2f-ed17446c1e92" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_019f8f48-41c0-7afe-8c2f-ed17446c1e92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_019f8f48-41c0-7750-a2c5-9a70ef1508ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TypeOfRestructuringDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_019f8f48-41c0-7afe-8c2f-ed17446c1e92" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_019f8f48-41c0-7750-a2c5-9a70ef1508ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember_019f8f48-41c0-71af-a43e-a887f2fe84e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_019f8f48-41c0-7750-a2c5-9a70ef1508ed" xlink:to="loc_us-gaap_EmployeeSeveranceMember_019f8f48-41c0-71af-a43e-a887f2fe84e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_019f8f48-41c0-77a7-a09c-2a019a297c12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringAndRelatedCostExpectedCost1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7d11-a096-f664faf4aeae" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCost1_019f8f48-41c0-77a7-a09c-2a019a297c12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_019f8f48-41c0-7660-8664-511df78920c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringAndRelatedCostCostIncurredToDate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7d11-a096-f664faf4aeae" xlink:to="loc_us-gaap_RestructuringAndRelatedCostCostIncurredToDate1_019f8f48-41c0-7660-8664-511df78920c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019f8f48-41c0-7b69-89fa-05efc5facac2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7d11-a096-f664faf4aeae" xlink:to="loc_us-gaap_RestructuringCharges_019f8f48-41c0-7b69-89fa-05efc5facac2" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/RESTRUCTURINGScheduleofRestructuringChargesDetails" xlink:type="simple" xlink:href="wab-20260930.xsd#RESTRUCTURINGScheduleofRestructuringChargesDetails"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/RESTRUCTURINGScheduleofRestructuringChargesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f8f48-41c0-7861-b86b-c92184bb11fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f8f48-41c0-7861-b86b-c92184bb11fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-7815-9af6-71ea0468093d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-7815-9af6-71ea0468093d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_019f8f48-41c0-77ab-88bb-6f6fc723f6c7" xlink:href="wab-20260930.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:to="loc_wab_FreightSegmentMember_019f8f48-41c0-77ab-88bb-6f6fc723f6c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_019f8f48-41c0-7ada-af3d-793e8d1a91d6" xlink:href="wab-20260930.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:to="loc_wab_TransitSegmentMember_019f8f48-41c0-7ada-af3d-793e8d1a91d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:to="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7179-b9ed-d23e4538478b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:to="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7179-b9ed-d23e4538478b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7402-a0d8-5d958bb356f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:to="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7402-a0d8-5d958bb356f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_Integration3.0Member_019f8f48-41c0-76d6-8eac-374199b47dfd" xlink:href="wab-20260930.xsd#wab_Integration3.0Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7402-a0d8-5d958bb356f8" xlink:to="loc_wab_Integration3.0Member_019f8f48-41c0-76d6-8eac-374199b47dfd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:to="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-780f-83ec-8040c9f477c5_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:to="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-780f-83ec-8040c9f477c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:to="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f8f48-41c0-7ef0-9f3d-3fdfd49b5364" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f8f48-41c0-7ef0-9f3d-3fdfd49b5364" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019f8f48-41c0-7940-9a2c-82a3ee3b4f53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019f8f48-41c0-7940-9a2c-82a3ee3b4f53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019f8f48-41c0-767f-9cef-7bbe993c4c61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:to="loc_us-gaap_RestructuringCharges_019f8f48-41c0-767f-9cef-7bbe993c4c61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019f8f48-41c0-7ee1-a22c-9a1312738fb2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:to="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019f8f48-41c0-7ee1-a22c-9a1312738fb2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.wabtec.com/role/RESTRUCTURINGScheduleofRestructuringChargesDetails_1" xlink:type="simple" xlink:href="wab-20260930.xsd#RESTRUCTURINGScheduleofRestructuringChargesDetails_1"/>
  <link:definitionLink xlink:role="http://www.wabtec.com/role/RESTRUCTURINGScheduleofRestructuringChargesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-7815-9af6-71ea0468093d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-7815-9af6-71ea0468093d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8f48-41c0-7815-9af6-71ea0468093d" xlink:to="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_019f8f48-41c0-77ab-88bb-6f6fc723f6c7" xlink:href="wab-20260930.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:to="loc_wab_FreightSegmentMember_019f8f48-41c0-77ab-88bb-6f6fc723f6c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_019f8f48-41c0-7ada-af3d-793e8d1a91d6" xlink:href="wab-20260930.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8f48-41c0-7351-abcb-b3c6f37bdf5d" xlink:to="loc_wab_TransitSegmentMember_019f8f48-41c0-7ada-af3d-793e8d1a91d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:to="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7179-b9ed-d23e4538478b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:to="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7179-b9ed-d23e4538478b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7402-a0d8-5d958bb356f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringPlanDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringPlanAxis_019f8f48-41c0-7179-b9ed-d23e4538478b" xlink:to="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7402-a0d8-5d958bb356f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_Integration3.0Member_019f8f48-41c0-76d6-8eac-374199b47dfd" xlink:href="wab-20260930.xsd#wab_Integration3.0Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringPlanDomain_019f8f48-41c0-7402-a0d8-5d958bb356f8" xlink:to="loc_wab_Integration3.0Member_019f8f48-41c0-76d6-8eac-374199b47dfd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_019f8f48-41c0-7411-abb0-f70693355af9" xlink:to="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-780f-83ec-8040c9f477c5_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:to="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-780f-83ec-8040c9f477c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019f8f48-41c0-780f-83ec-8040c9f477c5" xlink:to="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f8f48-41c0-7ef0-9f3d-3fdfd49b5364" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f8f48-41c0-7ef0-9f3d-3fdfd49b5364" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019f8f48-41c0-7940-9a2c-82a3ee3b4f53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8f48-41c0-7dba-bdf7-39270f757cc3" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019f8f48-41c0-7940-9a2c-82a3ee3b4f53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019f8f48-41c0-767f-9cef-7bbe993c4c61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:to="loc_us-gaap_RestructuringCharges_019f8f48-41c0-767f-9cef-7bbe993c4c61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019f8f48-41c0-7ee1-a22c-9a1312738fb2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_019f8f48-41c0-7483-bcee-5bd74aef35e1" xlink:to="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019f8f48-41c0-7ee1-a22c-9a1312738fb2" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
