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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019ecbda-f578-76d3-884f-5d71bdb456c8,g:5ca4fd0d-bd1b-4edf-8d93-84f097e1e03c-->
<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.enproindustries.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="simple" xlink:href="npo-20260630.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" 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_019ecbda-f6b8-7ab0-8db9-1de463c3082a" 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_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_StatementTable_019ecbda-f6b8-7ab0-8db9-1de463c3082a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_019ecbda-f6b8-7d5a-b1dd-8a519a6ea7f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ecbda-f6b8-7ab0-8db9-1de463c3082a" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_019ecbda-f6b8-7d5a-b1dd-8a519a6ea7f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ecbda-f6b8-7d5a-b1dd-8a519a6ea7f9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019ecbda-f6b8-7d5a-b1dd-8a519a6ea7f9" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ecbda-f6b8-7d5a-b1dd-8a519a6ea7f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ecbda-f6b8-7417-ab9a-c40a2ec98641" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019ecbda-f6b8-7d5a-b1dd-8a519a6ea7f9" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ecbda-f6b8-7417-ab9a-c40a2ec98641" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentMember_019ecbda-f6b8-7b21-b520-a77524e5a196" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ecbda-f6b8-7417-ab9a-c40a2ec98641" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentMember_019ecbda-f6b8-7b21-b520-a77524e5a196" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMember_019ecbda-f6b8-7ac2-8dd0-ef038e2a9694" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ecbda-f6b8-7417-ab9a-c40a2ec98641" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMember_019ecbda-f6b8-7ac2-8dd0-ef038e2a9694" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7498-bbaf-fc95b3b6a132" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7498-bbaf-fc95b3b6a132" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ecbda-f6b8-7db1-bcc2-236883c4cc9f" 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_NetCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7498-bbaf-fc95b3b6a132" xlink:to="loc_us-gaap_NetIncomeLoss_019ecbda-f6b8-7db1-bcc2-236883c4cc9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7498-bbaf-fc95b3b6a132" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_019ecbda-f6b8-7c39-ae15-03099249737a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:to="loc_us-gaap_Depreciation_019ecbda-f6b8-7c39-ae15-03099249737a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentForAmortization_019ecbda-f6b8-76bf-a1ff-f51f29e32d7b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentForAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:to="loc_us-gaap_AdjustmentForAmortization_019ecbda-f6b8-76bf-a1ff-f51f29e32d7b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019ecbda-f6b8-7e3d-af33-6a834ba1ec4f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019ecbda-f6b8-7e3d-af33-6a834ba1ec4f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019ecbda-f6b8-7a6a-8ce8-9ab65ae25f3f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:to="loc_us-gaap_ShareBasedCompensation_019ecbda-f6b8-7a6a-8ce8-9ab65ae25f3f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalExpenseAndLiabilities_019fafe8-7128-7e9b-a5d5-06fbc50fb15c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EnvironmentalExpenseAndLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:to="loc_us-gaap_EnvironmentalExpenseAndLiabilities_019fafe8-7128-7e9b-a5d5-06fbc50fb15c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_019ecbda-f6b8-754c-8be8-e2fc08079603" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_019ecbda-f6b8-754c-8be8-e2fc08079603" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019ecbda-f6b8-7063-8cd7-ba7fee83a153" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7b42-bbf9-31a383a73773" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019ecbda-f6b8-7063-8cd7-ba7fee83a153" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019ecbda-f6b8-7b69-9968-fcf53f98ec75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019ecbda-f6b8-7063-8cd7-ba7fee83a153" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019ecbda-f6b8-7b69-9968-fcf53f98ec75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_019ecbda-f6b8-7643-a818-e47c183ac109" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInInventories"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019ecbda-f6b8-7063-8cd7-ba7fee83a153" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_019ecbda-f6b8-7643-a818-e47c183ac109" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019ecbda-f6b8-7f95-bb8e-077292593fce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019ecbda-f6b8-7063-8cd7-ba7fee83a153" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_019ecbda-f6b8-7f95-bb8e-077292593fce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet_019ecbda-f6b8-7569-883b-e831cb2739ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019ecbda-f6b8-7063-8cd7-ba7fee83a153" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherCurrentAssetsAndLiabilitiesNet_019ecbda-f6b8-7569-883b-e831cb2739ca" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet_019ecbda-f6b8-74da-94ab-5cd3fdb0f18b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_019ecbda-f6b8-7063-8cd7-ba7fee83a153" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentAssetsAndLiabilitiesNet_019ecbda-f6b8-74da-94ab-5cd3fdb0f18b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ecbda-f6b8-7da3-a4ee-493e992a25c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_019ecbda-f6b8-7498-bbaf-fc95b3b6a132" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ecbda-f6b8-7da3-a4ee-493e992a25c0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019ecbda-f6b8-7191-a7f6-d499011fc11d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019ecbda-f6b8-7191-a7f6-d499011fc11d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForSoftware_019ecbda-f6b8-73e2-aa23-f94619a9cbee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForSoftware"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:to="loc_us-gaap_PaymentsForSoftware_019ecbda-f6b8-73e2-aa23-f94619a9cbee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfShortTermInvestments_019ecbda-f6b8-7f95-a50e-b4b0fee484aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfShortTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:to="loc_us-gaap_ProceedsFromSaleOfShortTermInvestments_019ecbda-f6b8-7f95-a50e-b4b0fee484aa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019f6e07-24d3-793a-b84a-8cdd248c2e2c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019f6e07-24d3-793a-b84a-8cdd248c2e2c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForHedgeInvestingActivities_019f6e07-24d3-7743-b37b-b6ef865f25c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForHedgeInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:to="loc_us-gaap_PaymentsForHedgeInvestingActivities_019f6e07-24d3-7743-b37b-b6ef865f25c6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_019ecbda-f6b8-71bf-a6e3-2377cd757177" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_019ecbda-f6b8-71bf-a6e3-2377cd757177" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ecbda-f6b8-7ba3-a118-4595f20119c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_019ecbda-f6b8-7720-8d4e-6105bf39765b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ecbda-f6b8-7ba3-a118-4595f20119c6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019f1bdc-708f-7ddf-be66-6620c093cbdf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019f1bdc-708f-7ddf-be66-6620c093cbdf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_019ecbda-f6b8-7a5a-b8da-555b15e8150a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_019ecbda-f6b8-7a5a-b8da-555b15e8150a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019f1bdc-708f-7958-a481-6ad0c80c1602" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019f1bdc-708f-7958-a481-6ad0c80c1602" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_019ecbda-f6b8-7d70-b1bb-eebf60f1cbd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_019ecbda-f6b8-7d70-b1bb-eebf60f1cbd4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_019ecbda-f6b8-7731-ae53-dd8c421283ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_019ecbda-f6b8-7731-ae53-dd8c421283ea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ecbda-f6b8-7d05-8adb-8e21c1a349b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_019ecbda-f6b8-7645-bc95-5db962a6fd8b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ecbda-f6b8-7d05-8adb-8e21c1a349b7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019ecbda-f6b8-7813-b34a-14807bd31aa6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019ecbda-f6b8-7813-b34a-14807bd31aa6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019ecbda-f6b8-782f-bc90-14d197797ead" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019ecbda-f6b8-782f-bc90-14d197797ead" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019ecbda-f6b8-76b4-8a9c-3bc5a66ad951" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019ecbda-f6b8-76b4-8a9c-3bc5a66ad951" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019ecbda-f6b8-7ee8-9ae6-b9b50354b832" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_019ecbda-f6b8-715d-bbe1-7772ebc5f8a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplementalCashFlowInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ecbda-f6b8-7262-8d0c-e5ac0d7b9d21" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_019ecbda-f6b8-715d-bbe1-7772ebc5f8a8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_CashPaidDuringPeriodForAbstract_019ecbda-f6b8-7e94-9a85-3a792b529f46" xlink:href="npo-20260630.xsd#npo_CashPaidDuringPeriodForAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_019ecbda-f6b8-715d-bbe1-7772ebc5f8a8" xlink:to="loc_npo_CashPaidDuringPeriodForAbstract_019ecbda-f6b8-7e94-9a85-3a792b529f46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet_019ecbda-f6b8-7a4e-b995-7989a8acd4c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_npo_CashPaidDuringPeriodForAbstract_019ecbda-f6b8-7e94-9a85-3a792b529f46" xlink:to="loc_us-gaap_InterestPaidNet_019ecbda-f6b8-7a4e-b995-7989a8acd4c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_019ecbda-f6b8-7b8a-9c3e-6290d5419a3b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxesPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_npo_CashPaidDuringPeriodForAbstract_019ecbda-f6b8-7e94-9a85-3a792b529f46" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_019ecbda-f6b8-7b8a-9c3e-6290d5419a3b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_019ecbda-f6b8-78eb-9edd-fd73344acc43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncashInvestingAndFinancingItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_019ecbda-f6b8-715d-bbe1-7772ebc5f8a8" xlink:to="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_019ecbda-f6b8-78eb-9edd-fd73344acc43" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_019ecbda-f6b8-7a72-9b9d-c44341fc4752" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashInvestingAndFinancingItemsAbstract_019ecbda-f6b8-78eb-9edd-fd73344acc43" xlink:to="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_019ecbda-f6b8-7a72-9b9d-c44341fc4752" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/AcquisitionsAdditionalInformationDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#AcquisitionsAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/AcquisitionsAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" 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_019ecbda-f6b8-7be2-92be-0959b046c6a1" 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_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ecbda-f6b8-7be2-92be-0959b046c6a1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ecbda-f6b8-719f-bc13-da1f58766883" 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_019ecbda-f6b8-7be2-92be-0959b046c6a1" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ecbda-f6b8-719f-bc13-da1f58766883" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-719f-bc13-da1f58766883_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_019ecbda-f6b8-719f-bc13-da1f58766883" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-719f-bc13-da1f58766883_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7045-937f-8f34a0e6533c" 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_019ecbda-f6b8-719f-bc13-da1f58766883" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7045-937f-8f34a0e6533c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_OverlookAndAlpHaMeasurementHoldingsAcquisitionsMember_019ecbda-f6b8-7275-b3e6-39c3e7453c42" xlink:href="npo-20260630.xsd#npo_OverlookAndAlpHaMeasurementHoldingsAcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7045-937f-8f34a0e6533c" xlink:to="loc_npo_OverlookAndAlpHaMeasurementHoldingsAcquisitionsMember_019ecbda-f6b8-7275-b3e6-39c3e7453c42" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019ecbda-f6b8-7e11-9142-49c3625d690a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019ecbda-f6b8-7e11-9142-49c3625d690a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfBusinessesAcquired_019ecbda-f6b8-78b4-8a75-a91c37950827" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfBusinessesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_us-gaap_NumberOfBusinessesAcquired_019ecbda-f6b8-78b4-8a75-a91c37950827" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_BusinessCombinationProvisionalInformationAccountingIncompleteAdjustmentWorkingCapital_019f6e39-358a-7246-803e-a064152aa432" xlink:href="npo-20260630.xsd#npo_BusinessCombinationProvisionalInformationAccountingIncompleteAdjustmentWorkingCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_npo_BusinessCombinationProvisionalInformationAccountingIncompleteAdjustmentWorkingCapital_019f6e39-358a-7246-803e-a064152aa432" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ecbda-f6b8-78e9-9f5b-1b01473660fe" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_us-gaap_Goodwill_019ecbda-f6b8-78e9-9f5b-1b01473660fe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_BusinessCombinationGoodwillPortionExpectedTaxDeductiblePercent_019ecbda-f6b8-73f9-8d75-23eee8d6973d" xlink:href="npo-20260630.xsd#npo_BusinessCombinationGoodwillPortionExpectedTaxDeductiblePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_npo_BusinessCombinationGoodwillPortionExpectedTaxDeductiblePercent_019ecbda-f6b8-73f9-8d75-23eee8d6973d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_019ecbda-f6b8-705e-a3f5-42339127725d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory_019ecbda-f6b8-705e-a3f5-42339127725d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAmortizedToCostOfGoodsSold_019ecbda-f6b8-7491-bc8c-881a7ac2f1c9" xlink:href="npo-20260630.xsd#npo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAmortizedToCostOfGoodsSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_npo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAmortizedToCostOfGoodsSold_019ecbda-f6b8-7491-bc8c-881a7ac2f1c9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentWorkingCapitalAdjustment_019ecbda-f6b8-7a5b-8b29-fdf5e208486c" xlink:href="npo-20260630.xsd#npo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentWorkingCapitalAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_npo_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentWorkingCapitalAdjustment_019ecbda-f6b8-7a5b-8b29-fdf5e208486c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019ecbda-f6b8-7b33-8e0c-3087e92a0e80" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-7b56-ba06-a2c2a5a31af3" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019ecbda-f6b8-7b33-8e0c-3087e92a0e80" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/AcquisitionsScheduleofBusinessCombinationRecognizedAssetAcquiredandLiabilityAssumedDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#AcquisitionsScheduleofBusinessCombinationRecognizedAssetAcquiredandLiabilityAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/AcquisitionsScheduleofBusinessCombinationRecognizedAssetAcquiredandLiabilityAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" 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_019ecbda-f6b8-7894-81d7-8c3591e4af74" 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_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ecbda-f6b8-7894-81d7-8c3591e4af74" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ecbda-f6b8-754c-b626-38e6c2bdf378" 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_019ecbda-f6b8-7894-81d7-8c3591e4af74" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ecbda-f6b8-754c-b626-38e6c2bdf378" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-754c-b626-38e6c2bdf378_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_019ecbda-f6b8-754c-b626-38e6c2bdf378" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-754c-b626-38e6c2bdf378_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-76af-9ece-6ff4d5b8f3cd" 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_019ecbda-f6b8-754c-b626-38e6c2bdf378" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-76af-9ece-6ff4d5b8f3cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_OverlookAndAlpHaMeasurementHoldingsAcquisitionsMember_019ecbda-f6b8-7c5f-bed2-321bbddddd53" xlink:href="npo-20260630.xsd#npo_OverlookAndAlpHaMeasurementHoldingsAcquisitionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-76af-9ece-6ff4d5b8f3cd" xlink:to="loc_npo_OverlookAndAlpHaMeasurementHoldingsAcquisitionsMember_019ecbda-f6b8-7c5f-bed2-321bbddddd53" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019ecbda-f6b8-7302-838b-ea9d8cc00e6c" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019ecbda-f6b8-7302-838b-ea9d8cc00e6c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_019ecbda-f6b8-7a16-9744-0f36208863e2" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_019ecbda-f6b8-7a16-9744-0f36208863e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019ecbda-f6b8-7030-bc81-f26de291cf6c" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019ecbda-f6b8-7030-bc81-f26de291cf6c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ecbda-f6b8-7f56-aa4d-70ec08623943" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_Goodwill_019ecbda-f6b8-7f56-aa4d-70ec08623943" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_019ecbda-f6b8-7ecb-9f2a-c0dfaed5bd4b" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_019ecbda-f6b8-7ecb-9f2a-c0dfaed5bd4b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_019ecbda-f6b8-7c10-bd62-3adb4aedebea" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_019ecbda-f6b8-7c10-bd62-3adb4aedebea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_019ecbda-f6b8-7ce7-af46-58e231eab765" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_019ecbda-f6b8-7ce7-af46-58e231eab765" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019ecbda-f6b8-7f76-986b-50ecf379a7a7" 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_BusinessAcquisitionLineItems_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019ecbda-f6b8-7f76-986b-50ecf379a7a7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019ecbda-f6b8-735d-bcbe-b0b7e4a66561" 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_019ecbda-f6b8-721e-8bb9-54fa3a96d195" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019ecbda-f6b8-735d-bcbe-b0b7e4a66561" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/AcquisitionsScheduleofBusinessAcquisitionProFormaInformationDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#AcquisitionsScheduleofBusinessAcquisitionProFormaInformationDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/AcquisitionsScheduleofBusinessAcquisitionProFormaInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-71b0-9f8c-51d738053aa6" 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_019ecbda-f6b8-77cd-87c9-c4f53f5f6e61" 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_019ecbda-f6b8-71b0-9f8c-51d738053aa6" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ecbda-f6b8-77cd-87c9-c4f53f5f6e61" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ecbda-f6b8-7dbc-9f97-243b12cffcf5" 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_019ecbda-f6b8-77cd-87c9-c4f53f5f6e61" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ecbda-f6b8-7dbc-9f97-243b12cffcf5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7dbc-9f97-243b12cffcf5_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_019ecbda-f6b8-7dbc-9f97-243b12cffcf5" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7dbc-9f97-243b12cffcf5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7197-b90b-30ec1d55cc88" 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_019ecbda-f6b8-7dbc-9f97-243b12cffcf5" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7197-b90b-30ec1d55cc88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdvancedMicroInstrumentsIncMember_019ecbda-f6b8-7497-a771-451a171c79bc" xlink:href="npo-20260630.xsd#npo_AdvancedMicroInstrumentsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ecbda-f6b8-7197-b90b-30ec1d55cc88" xlink:to="loc_npo_AdvancedMicroInstrumentsIncMember_019ecbda-f6b8-7497-a771-451a171c79bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_019ecbda-f6b8-75f0-aab2-51ebd99450be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionProFormaInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ecbda-f6b8-71b0-9f8c-51d738053aa6" xlink:to="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_019ecbda-f6b8-75f0-aab2-51ebd99450be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019ecbda-f6b8-7989-8209-fe3879ebc77c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_019ecbda-f6b8-75f0-aab2-51ebd99450be" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019ecbda-f6b8-7989-8209-fe3879ebc77c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019ecbda-f6b8-7380-8fa6-d1a93740b300" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionProFormaInformationAbstract_019ecbda-f6b8-75f0-aab2-51ebd99450be" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019ecbda-f6b8-7380-8fa6-d1a93740b300" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/GoodwillandOtherIntangibleAssetsScheduleofChangesinNetCarryingValueofGoodwillbyReportableSegmentDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#GoodwillandOtherIntangibleAssetsScheduleofChangesinNetCarryingValueofGoodwillbyReportableSegmentDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/GoodwillandOtherIntangibleAssetsScheduleofChangesinNetCarryingValueofGoodwillbyReportableSegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_019ecbda-f6b8-7e7b-890d-450212150630" 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_019ecbda-f6b8-78cf-af6b-dd5205c01eec" 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_019ecbda-f6b8-7e7b-890d-450212150630" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019ecbda-f6b8-78cf-af6b-dd5205c01eec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f6b8-731d-bd10-fc3d2fd93815" 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_019ecbda-f6b8-78cf-af6b-dd5205c01eec" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f6b8-731d-bd10-fc3d2fd93815" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f6b8-731d-bd10-fc3d2fd93815_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_019ecbda-f6b8-731d-bd10-fc3d2fd93815" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f6b8-731d-bd10-fc3d2fd93815_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f6b8-75da-b93a-aadb31f5f594" 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_019ecbda-f6b8-731d-bd10-fc3d2fd93815" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f6b8-75da-b93a-aadb31f5f594" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f6b8-76cf-9d2a-bc7b19d6b5e5" xlink:href="npo-20260630.xsd#npo_SealingTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f6b8-75da-b93a-aadb31f5f594" xlink:to="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f6b8-76cf-9d2a-bc7b19d6b5e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f6b8-7fed-b0f8-9051200d53aa" xlink:href="npo-20260630.xsd#npo_AdvancedSurfaceTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f6b8-75da-b93a-aadb31f5f594" xlink:to="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f6b8-7fed-b0f8-9051200d53aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_019ecbda-f6b8-7b43-84df-e8c955f1761a" 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_019ecbda-f6b8-7e7b-890d-450212150630" xlink:to="loc_us-gaap_GoodwillRollForward_019ecbda-f6b8-7b43-84df-e8c955f1761a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ecbda-f6b8-7b20-94aa-33cf02a80b9e" 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_019ecbda-f6b8-7b43-84df-e8c955f1761a" xlink:to="loc_us-gaap_Goodwill_019ecbda-f6b8-7b20-94aa-33cf02a80b9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019ecbda-f6b8-7280-bac0-76e9ed2773f2" 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_019ecbda-f6b8-7b43-84df-e8c955f1761a" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019ecbda-f6b8-7280-bac0-76e9ed2773f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019ecbda-f6b8-7ff1-bf1e-a510e14c0e59" 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_019ecbda-f6b8-7b43-84df-e8c955f1761a" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_019ecbda-f6b8-7ff1-bf1e-a510e14c0e59" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ecbda-f6b8-7964-b277-36fa807ed5c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/GoodwillandOtherIntangibleAssetsAdditionalInformationDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#GoodwillandOtherIntangibleAssetsAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/GoodwillandOtherIntangibleAssetsAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-74d7-a118-f319a63269b1" 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_019ecbda-f6b8-787b-bd6c-460da920f8ff" 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_019ecbda-f6b8-74d7-a118-f319a63269b1" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ecbda-f6b8-787b-bd6c-460da920f8ff" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f6b8-765e-8316-b335b2791a79" 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_019ecbda-f6b8-787b-bd6c-460da920f8ff" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f6b8-765e-8316-b335b2791a79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f6b8-765e-8316-b335b2791a79_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_019ecbda-f6b8-765e-8316-b335b2791a79" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f6b8-765e-8316-b335b2791a79_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7bbc-b734-82c38ce623d7" 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_019ecbda-f6b8-765e-8316-b335b2791a79" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7bbc-b734-82c38ce623d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f6b8-713a-81c7-cca203f7e943" xlink:href="npo-20260630.xsd#npo_SealingTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7bbc-b734-82c38ce623d7" xlink:to="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f6b8-713a-81c7-cca203f7e943" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f6b8-7d23-89a5-6b525233f2ee" xlink:href="npo-20260630.xsd#npo_AdvancedSurfaceTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7bbc-b734-82c38ce623d7" xlink:to="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f6b8-7d23-89a5-6b525233f2ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_019ecbda-f6b8-717a-b3d3-beeb7753b3c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillImpairedAccumulatedImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-74d7-a118-f319a63269b1" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_019ecbda-f6b8-717a-b3d3-beeb7753b3c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019ecbda-f6b8-7f57-bec3-605a4826f62c" 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_019ecbda-f6b8-74d7-a118-f319a63269b1" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019ecbda-f6b8-7f57-bec3-605a4826f62c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/GoodwillandOtherIntangibleAssetsScheduleofIdentifiableIntangibleAssetsDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#GoodwillandOtherIntangibleAssetsScheduleofIdentifiableIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/GoodwillandOtherIntangibleAssetsScheduleofIdentifiableIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ecbda-f6b8-7005-a3ef-3a584ddce30f" 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_019ecbda-f6b8-74e1-af00-f0f0dbd27638" 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_019ecbda-f6b8-7005-a3ef-3a584ddce30f" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019ecbda-f6b8-74e1-af00-f0f0dbd27638" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ecbda-f6b8-7f39-aecd-66efd904db38" 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_019ecbda-f6b8-74e1-af00-f0f0dbd27638" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019ecbda-f6b8-7f39-aecd-66efd904db38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7f39-aecd-66efd904db38_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_019ecbda-f6b8-7f39-aecd-66efd904db38" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7f39-aecd-66efd904db38_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-77a1-9696-45749de77709" 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_019ecbda-f6b8-7f39-aecd-66efd904db38" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-77a1-9696-45749de77709" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019ecbda-f6b8-7a4a-91d5-3bdb467331bc" 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_019ecbda-f6b8-77a1-9696-45749de77709" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019ecbda-f6b8-7a4a-91d5-3bdb467331bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnpatentedTechnologyMember_019ecbda-f6b8-7832-add4-4298966ad13a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnpatentedTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-77a1-9696-45749de77709" xlink:to="loc_us-gaap_UnpatentedTechnologyMember_019ecbda-f6b8-7832-add4-4298966ad13a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_019ecbda-f6b8-70ca-9ee4-9b173a53ecaf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-77a1-9696-45749de77709" xlink:to="loc_us-gaap_TrademarksMember_019ecbda-f6b8-70ca-9ee4-9b173a53ecaf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_019ecbda-f6b8-78c7-baab-c74e2d17bc78" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-77a1-9696-45749de77709" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_019ecbda-f6b8-78c7-baab-c74e2d17bc78" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019ecbda-f6b8-7716-a45d-0cbc924ea9eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019ecbda-f6b8-74e1-af00-f0f0dbd27638" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019ecbda-f6b8-7716-a45d-0cbc924ea9eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7716-a45d-0cbc924ea9eb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019ecbda-f6b8-7716-a45d-0cbc924ea9eb" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7716-a45d-0cbc924ea9eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7b22-819b-c8b8e1fd95fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_019ecbda-f6b8-7716-a45d-0cbc924ea9eb" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7b22-819b-c8b8e1fd95fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InProcessResearchAndDevelopmentMember_019ecbda-f6b8-7886-ac67-57167da614d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InProcessResearchAndDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7b22-819b-c8b8e1fd95fd" xlink:to="loc_us-gaap_InProcessResearchAndDevelopmentMember_019ecbda-f6b8-7886-ac67-57167da614d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_019ecbda-f6b8-7102-9423-8997442029f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_019ecbda-f6b8-7b22-819b-c8b8e1fd95fd" xlink:to="loc_us-gaap_TrademarksMember_019ecbda-f6b8-7102-9423-8997442029f9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019ecbda-f6b8-79cc-9b1d-c371f24fe82a" 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_019ecbda-f6b8-7005-a3ef-3a584ddce30f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019ecbda-f6b8-79cc-9b1d-c371f24fe82a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019ecbda-f6b8-7fa7-a7ce-a3c51307724d" 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_019ecbda-f6b8-7005-a3ef-3a584ddce30f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019ecbda-f6b8-7fa7-a7ce-a3c51307724d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_019ecbda-f6b8-7a7d-91ed-a3151a0d6d55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ecbda-f6b8-7005-a3ef-3a584ddce30f" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_019ecbda-f6b8-7a7d-91ed-a3151a0d6d55" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019ecbda-f6b8-7a07-ab76-bc5e786fb94e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019ecbda-f6b8-7005-a3ef-3a584ddce30f" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_019ecbda-f6b8-7a07-ab76-bc5e786fb94e" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/LongTermDebtDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#LongTermDebtDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/LongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_019ecbda-f6b8-76dd-a04c-1d6015bc830f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_019ecbda-f6b8-76dd-a04c-1d6015bc830f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019ecbda-f6b8-793e-bb48-a2520d91b925" 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_LineOfCreditFacilityTable_019ecbda-f6b8-76dd-a04c-1d6015bc830f" xlink:to="loc_us-gaap_DebtInstrumentAxis_019ecbda-f6b8-793e-bb48-a2520d91b925" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-793e-bb48-a2520d91b925_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_019ecbda-f6b8-793e-bb48-a2520d91b925" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-793e-bb48-a2520d91b925_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-732e-9ef0-facefc0f7288" 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_019ecbda-f6b8-793e-bb48-a2520d91b925" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-732e-9ef0-facefc0f7288" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AmendedAndRestatedCreditAgreementMember_019ecbda-f6b8-7e65-a8eb-14a974547952" xlink:href="npo-20260630.xsd#npo_AmendedAndRestatedCreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-732e-9ef0-facefc0f7288" xlink:to="loc_npo_AmendedAndRestatedCreditAgreementMember_019ecbda-f6b8-7e65-a8eb-14a974547952" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_TermLoanMember_019ecbda-f6b8-73c3-9a18-9fa251a08b3d" xlink:href="npo-20260630.xsd#npo_TermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-732e-9ef0-facefc0f7288" xlink:to="loc_npo_TermLoanMember_019ecbda-f6b8-73c3-9a18-9fa251a08b3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019ecbda-f6b8-73a2-bcb1-fd0caec14eaa" 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_DebtInstrumentNameDomain_019ecbda-f6b8-732e-9ef0-facefc0f7288" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019ecbda-f6b8-73a2-bcb1-fd0caec14eaa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SeniorNotes6.125DueJune2033Member_019ecbda-f6b8-7e9d-bcaf-ff51ea3c669d" xlink:href="npo-20260630.xsd#npo_SeniorNotes6.125DueJune2033Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-732e-9ef0-facefc0f7288" xlink:to="loc_npo_SeniorNotes6.125DueJune2033Member_019ecbda-f6b8-7e9d-bcaf-ff51ea3c669d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SeniorNotes5.75DueJune2025Member_019ecbda-f6b8-7166-b316-380da3d372ef" xlink:href="npo-20260630.xsd#npo_SeniorNotes5.75DueJune2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019ecbda-f6b8-732e-9ef0-facefc0f7288" xlink:to="loc_npo_SeniorNotes5.75DueJune2025Member_019ecbda-f6b8-7166-b316-380da3d372ef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019ecbda-f6b8-711f-a63a-71802af25ccf" 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_LineOfCreditFacilityTable_019ecbda-f6b8-76dd-a04c-1d6015bc830f" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019ecbda-f6b8-711f-a63a-71802af25ccf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019ecbda-f6b8-711f-a63a-71802af25ccf_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_019ecbda-f6b8-711f-a63a-71802af25ccf" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019ecbda-f6b8-711f-a63a-71802af25ccf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019ecbda-f6b8-7482-ab44-238f5e3553fc" 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_019ecbda-f6b8-711f-a63a-71802af25ccf" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019ecbda-f6b8-7482-ab44-238f5e3553fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019ecbda-f6b8-7891-9c2a-007ddca6b88e" 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_019ecbda-f6b8-7482-ab44-238f5e3553fc" xlink:to="loc_us-gaap_LineOfCreditMember_019ecbda-f6b8-7891-9c2a-007ddca6b88e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019ecbda-f6b8-76cb-9353-25c6729159d1" 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_019ecbda-f6b8-7482-ab44-238f5e3553fc" xlink:to="loc_us-gaap_SeniorNotesMember_019ecbda-f6b8-76cb-9353-25c6729159d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_DebtInstrumentVariableRateScenarioAxis_019ecbda-f6b8-7e66-bd7e-3fa07ff8d450" xlink:href="npo-20260630.xsd#npo_DebtInstrumentVariableRateScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019ecbda-f6b8-76dd-a04c-1d6015bc830f" xlink:to="loc_npo_DebtInstrumentVariableRateScenarioAxis_019ecbda-f6b8-7e66-bd7e-3fa07ff8d450" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_DebtInstrumentVariableRateScenarioDomain_019ecbda-f6b8-7e66-bd7e-3fa07ff8d450_default" xlink:href="npo-20260630.xsd#npo_DebtInstrumentVariableRateScenarioDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_npo_DebtInstrumentVariableRateScenarioAxis_019ecbda-f6b8-7e66-bd7e-3fa07ff8d450" xlink:to="loc_npo_DebtInstrumentVariableRateScenarioDomain_019ecbda-f6b8-7e66-bd7e-3fa07ff8d450_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_DebtInstrumentVariableRateScenarioDomain_019ecbda-f6b8-7c15-9ade-2eb2f8a1f67a" xlink:href="npo-20260630.xsd#npo_DebtInstrumentVariableRateScenarioDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_npo_DebtInstrumentVariableRateScenarioAxis_019ecbda-f6b8-7e66-bd7e-3fa07ff8d450" xlink:to="loc_npo_DebtInstrumentVariableRateScenarioDomain_019ecbda-f6b8-7c15-9ade-2eb2f8a1f67a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_VariableRateScenarioOneMember_019ecbda-f6b8-743c-9208-abc1b9b28358" xlink:href="npo-20260630.xsd#npo_VariableRateScenarioOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_npo_DebtInstrumentVariableRateScenarioDomain_019ecbda-f6b8-7c15-9ade-2eb2f8a1f67a" xlink:to="loc_npo_VariableRateScenarioOneMember_019ecbda-f6b8-743c-9208-abc1b9b28358" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_VariableRateScenarioTwoMember_019ecbda-f6b8-7c88-8bf9-93c298eb5d0c" xlink:href="npo-20260630.xsd#npo_VariableRateScenarioTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_npo_DebtInstrumentVariableRateScenarioDomain_019ecbda-f6b8-7c15-9ade-2eb2f8a1f67a" xlink:to="loc_npo_VariableRateScenarioTwoMember_019ecbda-f6b8-7c88-8bf9-93c298eb5d0c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019ecbda-f6b8-7ebe-832a-b7536f15d711" 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_LineOfCreditFacilityTable_019ecbda-f6b8-76dd-a04c-1d6015bc830f" xlink:to="loc_us-gaap_CreditFacilityAxis_019ecbda-f6b8-7ebe-832a-b7536f15d711" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019ecbda-f6b8-7ebe-832a-b7536f15d711_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_019ecbda-f6b8-7ebe-832a-b7536f15d711" xlink:to="loc_us-gaap_CreditFacilityDomain_019ecbda-f6b8-7ebe-832a-b7536f15d711_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019ecbda-f6b8-778b-97a3-e366fbe20472" 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_019ecbda-f6b8-7ebe-832a-b7536f15d711" xlink:to="loc_us-gaap_CreditFacilityDomain_019ecbda-f6b8-778b-97a3-e366fbe20472" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019ecbda-f6b8-731c-88b7-66f0bfc615b0" 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_019ecbda-f6b8-778b-97a3-e366fbe20472" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019ecbda-f6b8-731c-88b7-66f0bfc615b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019ecbda-f6b8-798b-a18c-3b0191de0c0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019ecbda-f6b8-76dd-a04c-1d6015bc830f" xlink:to="loc_us-gaap_VariableRateAxis_019ecbda-f6b8-798b-a18c-3b0191de0c0c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019ecbda-f6b8-798b-a18c-3b0191de0c0c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019ecbda-f6b8-798b-a18c-3b0191de0c0c" xlink:to="loc_us-gaap_VariableRateDomain_019ecbda-f6b8-798b-a18c-3b0191de0c0c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019ecbda-f6b8-783f-9abc-6b01ca2fcd7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019ecbda-f6b8-798b-a18c-3b0191de0c0c" xlink:to="loc_us-gaap_VariableRateDomain_019ecbda-f6b8-783f-9abc-6b01ca2fcd7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_FederalFundsEffectiveRateMember_019ecbda-f6b8-7ffe-9c7b-8d894a54f728" xlink:href="npo-20260630.xsd#npo_FederalFundsEffectiveRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019ecbda-f6b8-783f-9abc-6b01ca2fcd7e" xlink:to="loc_npo_FederalFundsEffectiveRateMember_019ecbda-f6b8-7ffe-9c7b-8d894a54f728" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019ecbda-f6b8-7364-be05-49724944b807" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredOvernightFinancingRateSofrMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019ecbda-f6b8-783f-9abc-6b01ca2fcd7e" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrMember_019ecbda-f6b8-7364-be05-49724944b807" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_019ecbda-f6b8-7400-8a1c-15ac8adfdbef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_019ecbda-f6b8-783f-9abc-6b01ca2fcd7e" xlink:to="loc_us-gaap_BaseRateMember_019ecbda-f6b8-7400-8a1c-15ac8adfdbef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019ecbda-f6b8-7454-b6dc-b62d9834a0ff" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019ecbda-f6b8-7454-b6dc-b62d9834a0ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_019ecbda-f6b8-7a2c-82bd-12501d644b6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_019ecbda-f6b8-7a2c-82bd-12501d644b6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LineOfCreditFacilityAccordionFeatureIncreaseLimit_019ecbda-f6b8-7c68-8337-c2672a5ec0a6" xlink:href="npo-20260630.xsd#npo_LineOfCreditFacilityAccordionFeatureIncreaseLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_npo_LineOfCreditFacilityAccordionFeatureIncreaseLimit_019ecbda-f6b8-7c68-8337-c2672a5ec0a6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LineOfCreditFacilityAccordionFeatureIncreaseLimitPercentageOfEBITDA_019ecbda-f6b8-7365-92a6-23a256cb6728" xlink:href="npo-20260630.xsd#npo_LineOfCreditFacilityAccordionFeatureIncreaseLimitPercentageOfEBITDA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_npo_LineOfCreditFacilityAccordionFeatureIncreaseLimitPercentageOfEBITDA_019ecbda-f6b8-7365-92a6-23a256cb6728" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019ecbda-f6b8-7ba8-802c-4e6dc4cdb682" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_019ecbda-f6b8-7ba8-802c-4e6dc4cdb682" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019ecbda-f6b8-7874-a79c-ffa9c3f5977c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_019ecbda-f6b8-7874-a79c-ffa9c3f5977c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019ecbda-f6b8-79f7-94f0-7af4c7c04244" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_019ecbda-f6b8-79f7-94f0-7af4c7c04244" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019ecbda-f6b8-7d92-88ad-86653c6e127e" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019ecbda-f6b8-7d92-88ad-86653c6e127e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019ecbda-f6b8-7dda-976e-3360e413cfaa" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_LongTermDebt_019ecbda-f6b8-7dda-976e-3360e413cfaa" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019ecbda-f6b8-72b8-b12c-376ae0e6d1df" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019ecbda-f6b8-72b8-b12c-376ae0e6d1df" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019ecbda-f6b8-7851-98dc-0fbb2403e8ef" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019ecbda-f6b8-7851-98dc-0fbb2403e8ef" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_019ecbda-f6b8-72a3-b1e1-e78b7ed460a5" 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_LineOfCreditFacilityLineItems_019ecbda-f6b8-7b2b-8118-38f03d4e9319" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_019ecbda-f6b8-72a3-b1e1-e78b7ed460a5" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/ShareholdersEquityScheduleofChangesinShareholdersEquityDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#ShareholdersEquityScheduleofChangesinShareholdersEquityDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/ShareholdersEquityScheduleofChangesinShareholdersEquityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019ecbda-f6b8-7040-862e-9a5ca2ecd1fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019ecbda-f6b8-7477-bf58-d09177865449" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ecbda-f6b8-7040-862e-9a5ca2ecd1fa" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019ecbda-f6b8-7477-bf58-d09177865449" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019ecbda-f6b8-789a-acae-00f25aa9aeca" 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_ScheduleOfStockByClassTable_019ecbda-f6b8-7477-bf58-d09177865449" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019ecbda-f6b8-789a-acae-00f25aa9aeca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ecbda-f6b8-789a-acae-00f25aa9aeca_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_019ecbda-f6b8-789a-acae-00f25aa9aeca" xlink:to="loc_us-gaap_EquityComponentDomain_019ecbda-f6b8-789a-acae-00f25aa9aeca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ecbda-f6b8-77fa-a031-9751b132e616" 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_019ecbda-f6b8-789a-acae-00f25aa9aeca" xlink:to="loc_us-gaap_EquityComponentDomain_019ecbda-f6b8-77fa-a031-9751b132e616" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019ecbda-f6b8-7a62-876b-826940d96f77" 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_019ecbda-f6b8-77fa-a031-9751b132e616" xlink:to="loc_us-gaap_CommonStockMember_019ecbda-f6b8-7a62-876b-826940d96f77" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019ecbda-f6b8-7bae-8bb1-c95d8e53c92f" 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_019ecbda-f6b8-77fa-a031-9751b132e616" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019ecbda-f6b8-7bae-8bb1-c95d8e53c92f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019ecbda-f6b8-7111-ab94-fc2fd693cae5" 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_019ecbda-f6b8-77fa-a031-9751b132e616" xlink:to="loc_us-gaap_RetainedEarningsMember_019ecbda-f6b8-7111-ab94-fc2fd693cae5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ecbda-f6b8-7222-88a0-d46b36cdcf81" 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_019ecbda-f6b8-77fa-a031-9751b132e616" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ecbda-f6b8-7222-88a0-d46b36cdcf81" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019ecbda-f6b8-7552-9ab4-6582da587090" 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_019ecbda-f6b8-77fa-a031-9751b132e616" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019ecbda-f6b8-7552-9ab4-6582da587090" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ecbda-f6b8-7972-8f0b-c32c7271e015" 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_ClassOfStockLineItems_019ecbda-f6b8-7040-862e-9a5ca2ecd1fa" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ecbda-f6b8-7972-8f0b-c32c7271e015" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019ecbda-f6b8-7e01-bd4f-d718aa7ac5ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ecbda-f6b8-7972-8f0b-c32c7271e015" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019ecbda-f6b8-7e01-bd4f-d718aa7ac5ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ecbda-f6b8-7ba6-a945-64dfc233b4f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ecbda-f6b8-7972-8f0b-c32c7271e015" xlink:to="loc_us-gaap_StockholdersEquity_019ecbda-f6b8-7ba6-a945-64dfc233b4f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ecbda-f6b8-7a5e-8889-2c40133b9353" 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_IncreaseDecreaseInStockholdersEquityRollForward_019ecbda-f6b8-7972-8f0b-c32c7271e015" xlink:to="loc_us-gaap_NetIncomeLoss_019ecbda-f6b8-7a5e-8889-2c40133b9353" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ecbda-f6b8-799e-acfb-a67bc3d35e5f" 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_019ecbda-f6b8-7972-8f0b-c32c7271e015" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ecbda-f6b8-799e-acfb-a67bc3d35e5f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_019ecbda-f6b8-7335-bdc9-c207056ea25a" 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_019ecbda-f6b8-7972-8f0b-c32c7271e015" xlink:to="loc_us-gaap_DividendsCommonStockCash_019ecbda-f6b8-7335-bdc9-c207056ea25a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019ecbda-f6b8-71d8-88e5-5b10439699b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ecbda-f6b8-7972-8f0b-c32c7271e015" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019ecbda-f6b8-71d8-88e5-5b10439699b8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019ecbda-f6b8-738d-9973-ceb528d27027" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ecbda-f6b8-745e-ad0d-0a606b881260" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019ecbda-f6b8-7b7e-b2f3-b67fcc061087" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ecbda-f6b8-7040-862e-9a5ca2ecd1fa" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019ecbda-f6b8-7b7e-b2f3-b67fcc061087" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/ShareholdersEquityAdditionalInformationDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#ShareholdersEquityAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/ShareholdersEquityAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" 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_019ecbda-f6b8-78f3-bdcd-a1dca9033e9d" 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_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ecbda-f6b8-78f3-bdcd-a1dca9033e9d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_019ecbda-f6b8-76e7-aad2-af62bab99896" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ecbda-f6b8-78f3-bdcd-a1dca9033e9d" xlink:to="loc_srt_TitleOfIndividualAxis_019ecbda-f6b8-76e7-aad2-af62bab99896" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_019ecbda-f6b8-76e7-aad2-af62bab99896_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_019ecbda-f6b8-76e7-aad2-af62bab99896" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_019ecbda-f6b8-76e7-aad2-af62bab99896_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_019ecbda-f6b8-73fe-b1cb-99266779dc2d" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_019ecbda-f6b8-76e7-aad2-af62bab99896" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_019ecbda-f6b8-73fe-b1cb-99266779dc2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_KeyExecutivesMember_019ecbda-f6b8-7b3f-940d-18c239c5dbc2" xlink:href="npo-20260630.xsd#npo_KeyExecutivesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_019ecbda-f6b8-73fe-b1cb-99266779dc2d" xlink:to="loc_npo_KeyExecutivesMember_019ecbda-f6b8-7b3f-940d-18c239c5dbc2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ecbda-f6b8-71e3-bdfc-a98c68588bc5" 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_019ecbda-f6b8-78f3-bdcd-a1dca9033e9d" xlink:to="loc_us-gaap_AwardTypeAxis_019ecbda-f6b8-71e3-bdfc-a98c68588bc5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-71e3-bdfc-a98c68588bc5_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_019ecbda-f6b8-71e3-bdfc-a98c68588bc5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-71e3-bdfc-a98c68588bc5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-7518-9167-5b2d2cd7bf3d" 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_019ecbda-f6b8-71e3-bdfc-a98c68588bc5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-7518-9167-5b2d2cd7bf3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019ecbda-f6b8-745d-b28d-e31e017d5599" 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_019ecbda-f6b8-7518-9167-5b2d2cd7bf3d" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019ecbda-f6b8-745d-b28d-e31e017d5599" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019fb0f3-371a-7c22-be1f-31fcc7470e12" 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_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ecbda-f6b8-78f3-bdcd-a1dca9033e9d" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019fb0f3-371a-7c22-be1f-31fcc7470e12" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019fb0f3-371a-7c22-be1f-31fcc7470e12_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_019fb0f3-371a-7c22-be1f-31fcc7470e12" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019fb0f3-371a-7c22-be1f-31fcc7470e12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019fb0f3-371a-7e64-a2fe-fd92e99ed45e" 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_019fb0f3-371a-7c22-be1f-31fcc7470e12" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019fb0f3-371a-7e64-a2fe-fd92e99ed45e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019fb0f3-68a9-77fb-a71e-6828dbf26fda" 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_019fb0f3-371a-7e64-a2fe-fd92e99ed45e" xlink:to="loc_us-gaap_SubsequentEventMember_019fb0f3-68a9-77fb-a71e-6828dbf26fda" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019ecbda-f6b8-7706-a0e2-7804cab3469a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019ecbda-f6b8-7706-a0e2-7804cab3469a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_ShareRepurchaseProgramTermOfProgram_019ecbda-f6b8-7436-a8c2-7fb56c627b4b" xlink:href="npo-20260630.xsd#npo_ShareRepurchaseProgramTermOfProgram"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_npo_ShareRepurchaseProgramTermOfProgram_019ecbda-f6b8-7436-a8c2-7fb56c627b4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019ecbda-f6b8-79bb-83c9-edeb29093be3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019ecbda-f6b8-79bb-83c9-edeb29093be3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_019ecbda-f6b8-783f-a2d0-b0fa35e8a753" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_019ecbda-f6b8-783f-a2d0-b0fa35e8a753" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_019ecbda-f6b8-7fdf-8808-2a161f1c1e24" 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_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_019ecbda-f6b8-7fdf-8808-2a161f1c1e24" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_019ecbda-f6b8-75fd-afdb-e79082d3bcc9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_019ecbda-f6b8-75fd-afdb-e79082d3bcc9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019ecbda-f6b8-7fd9-adc8-d689a83ac216" 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_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_019ecbda-f6b8-7fd9-adc8-d689a83ac216" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019ecbda-f6b8-7562-a39e-87b70866d703" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019ecbda-f6b8-7562-a39e-87b70866d703" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019ecbda-f6b8-75ee-a383-99b8febc3d93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7616-8c1c-237d002bee0b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019ecbda-f6b8-75ee-a383-99b8febc3d93" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/ShareholdersEquityScheduleofFairValueofShareBasedValuationAssumptionsDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#ShareholdersEquityScheduleofFairValueofShareBasedValuationAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/ShareholdersEquityScheduleofFairValueofShareBasedValuationAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7f6c-94f7-5244f3b4c719" 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_019ecbda-f6b8-7b4c-a44d-5b7f70960bc0" 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_019ecbda-f6b8-7f6c-94f7-5244f3b4c719" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ecbda-f6b8-7b4c-a44d-5b7f70960bc0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ecbda-f6b8-7c96-a397-de8f89b71ff4" 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_019ecbda-f6b8-7b4c-a44d-5b7f70960bc0" xlink:to="loc_us-gaap_AwardTypeAxis_019ecbda-f6b8-7c96-a397-de8f89b71ff4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-7c96-a397-de8f89b71ff4_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_019ecbda-f6b8-7c96-a397-de8f89b71ff4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-7c96-a397-de8f89b71ff4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-7fc2-afe2-c08c131e25fa" 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_019ecbda-f6b8-7c96-a397-de8f89b71ff4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ecbda-f6b8-7fc2-afe2-c08c131e25fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019ecbda-f6b8-78c2-8b42-6141591738bf" 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_019ecbda-f6b8-7fc2-afe2-c08c131e25fa" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019ecbda-f6b8-78c2-8b42-6141591738bf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019ecbda-f6b8-7e58-b092-769af0b3c624" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7f6c-94f7-5244f3b4c719" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_019ecbda-f6b8-7e58-b092-769af0b3c624" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019ecbda-f6b8-7627-95af-692abee15f30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7f6c-94f7-5244f3b4c719" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_019ecbda-f6b8-7627-95af-692abee15f30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019ecbda-f6b8-7592-b4cf-a7e7631d59fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7f6c-94f7-5244f3b4c719" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_019ecbda-f6b8-7592-b4cf-a7e7631d59fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019ecbda-f6b8-7f7e-8677-0a3dacc0a2ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ecbda-f6b8-7f6c-94f7-5244f3b4c719" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_019ecbda-f6b8-7f7e-8677-0a3dacc0a2ea" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/BusinessSegmentInformationAdditionalInformationDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#BusinessSegmentInformationAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/BusinessSegmentInformationAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-77b4-bf43-a30ef2389527" 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_019ecbda-f6b8-711d-bdbd-e0ca030889b7" 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_019ecbda-f6b8-77b4-bf43-a30ef2389527" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ecbda-f6b8-711d-bdbd-e0ca030889b7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ecbda-f6b8-763f-b678-c3c17adf19e9" 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_019ecbda-f6b8-711d-bdbd-e0ca030889b7" xlink:to="loc_srt_ConsolidationItemsAxis_019ecbda-f6b8-763f-b678-c3c17adf19e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-763f-b678-c3c17adf19e9_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_019ecbda-f6b8-763f-b678-c3c17adf19e9" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-763f-b678-c3c17adf19e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-7b23-aff9-d79eb5a5a02f" 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_019ecbda-f6b8-763f-b678-c3c17adf19e9" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-7b23-aff9-d79eb5a5a02f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019ecbda-f6b8-7178-8b10-109726be3617" 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_019ecbda-f6b8-7b23-aff9-d79eb5a5a02f" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019ecbda-f6b8-7178-8b10-109726be3617" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019ecbda-f6b8-70e9-900c-352559a34b38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-77b4-bf43-a30ef2389527" xlink:to="loc_us-gaap_NumberOfReportableSegments_019ecbda-f6b8-70e9-900c-352559a34b38" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_019ecbda-f6b8-79e1-9d8d-be1da36d6fe4" 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_SegmentReportingInformationLineItems_019ecbda-f6b8-77b4-bf43-a30ef2389527" xlink:to="loc_us-gaap_RestructuringCharges_019ecbda-f6b8-79e1-9d8d-be1da36d6fe4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofSegmentOperatingResultsandOtherFinancialDataDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#BusinessSegmentInformationScheduleofSegmentOperatingResultsandOtherFinancialDataDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofSegmentOperatingResultsandOtherFinancialDataDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-7847-8a21-7aa2d9599a81" 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_019ecbda-f6b8-7536-9b8f-74da5cea5105" 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_019ecbda-f6b8-7847-8a21-7aa2d9599a81" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ecbda-f6b8-7536-9b8f-74da5cea5105" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ecbda-f6b8-7dd1-85b0-3280449e1167" 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_019ecbda-f6b8-7536-9b8f-74da5cea5105" xlink:to="loc_srt_ConsolidationItemsAxis_019ecbda-f6b8-7dd1-85b0-3280449e1167" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-7dd1-85b0-3280449e1167_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_019ecbda-f6b8-7dd1-85b0-3280449e1167" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-7dd1-85b0-3280449e1167_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-7168-9d05-4c7b3db2d6c7" 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_019ecbda-f6b8-7dd1-85b0-3280449e1167" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-7168-9d05-4c7b3db2d6c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019ecbda-f6b8-7adc-a9ea-f1c0003a08de" 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_019ecbda-f6b8-7168-9d05-4c7b3db2d6c7" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019ecbda-f6b8-7adc-a9ea-f1c0003a08de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ecbda-f6b8-7df6-87a1-5cc3f04a01f1" 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_019ecbda-f6b8-7168-9d05-4c7b3db2d6c7" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ecbda-f6b8-7df6-87a1-5cc3f04a01f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_019ecbda-f6b8-7d64-a986-248d165e445f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MaterialReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ecbda-f6b8-7168-9d05-4c7b3db2d6c7" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_019ecbda-f6b8-7d64-a986-248d165e445f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f6b8-7b45-b558-9bf8cd2dce07" 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_019ecbda-f6b8-7536-9b8f-74da5cea5105" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f6b8-7b45-b558-9bf8cd2dce07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7b45-b558-9bf8cd2dce07_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_019ecbda-f6b8-7b45-b558-9bf8cd2dce07" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7b45-b558-9bf8cd2dce07_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7d83-8b41-356ed202b0d2" 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_019ecbda-f6b8-7b45-b558-9bf8cd2dce07" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7d83-8b41-356ed202b0d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f6b8-7b8f-8e27-8ed1a2747409" xlink:href="npo-20260630.xsd#npo_SealingTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7d83-8b41-356ed202b0d2" xlink:to="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f6b8-7b8f-8e27-8ed1a2747409" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f6b8-791e-9558-1beffa83bd2c" xlink:href="npo-20260630.xsd#npo_AdvancedSurfaceTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f6b8-7d83-8b41-356ed202b0d2" xlink:to="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f6b8-791e-9558-1beffa83bd2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019ecbda-f6b8-7559-b370-e48667517681" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-7847-8a21-7aa2d9599a81" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019ecbda-f6b8-7559-b370-e48667517681" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019ecbda-f6b8-706f-b8d1-8bb2c0670857" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-7847-8a21-7aa2d9599a81" xlink:to="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019ecbda-f6b8-706f-b8d1-8bb2c0670857" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019ecbda-f6b8-7ba9-aaf4-979736ae7a73" 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_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019ecbda-f6b8-706f-b8d1-8bb2c0670857" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019ecbda-f6b8-7ba9-aaf4-979736ae7a73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019ecbda-f6b8-79bb-a7a6-71fca34c28e4" 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_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019ecbda-f6b8-706f-b8d1-8bb2c0670857" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019ecbda-f6b8-79bb-a7a6-71fca34c28e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostOfOperatingRevenue_019ecbda-f761-78fe-9367-eab05e725578" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCostOfOperatingRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationFromSegmentTotalsToConsolidatedAbstract_019ecbda-f6b8-706f-b8d1-8bb2c0670857" xlink:to="loc_us-gaap_OtherCostOfOperatingRevenue_019ecbda-f761-78fe-9367-eab05e725578" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SegmentReconciliationAdjustingItemsAbstract_019ecbda-f761-7639-bb84-eb63c0cef340" xlink:href="npo-20260630.xsd#npo_SegmentReconciliationAdjustingItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-7847-8a21-7aa2d9599a81" xlink:to="loc_npo_SegmentReconciliationAdjustingItemsAbstract_019ecbda-f761-7639-bb84-eb63c0cef340" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019ecbda-f761-77c3-8108-dc428a9ab200" 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_npo_SegmentReconciliationAdjustingItemsAbstract_019ecbda-f761-7639-bb84-eb63c0cef340" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019ecbda-f761-77c3-8108-dc428a9ab200" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_FairValueAdjustmentToAcquisitionDateInventory_019ecbda-f761-7b24-a5f6-dd078d9d6c42" xlink:href="npo-20260630.xsd#npo_FairValueAdjustmentToAcquisitionDateInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_npo_SegmentReconciliationAdjustingItemsAbstract_019ecbda-f761-7639-bb84-eb63c0cef340" xlink:to="loc_npo_FairValueAdjustmentToAcquisitionDateInventory_019ecbda-f761-7b24-a5f6-dd078d9d6c42" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_019ecbda-f761-7b61-8f02-7b86da122eb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostsAndAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_npo_SegmentReconciliationAdjustingItemsAbstract_019ecbda-f761-7639-bb84-eb63c0cef340" xlink:to="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_019ecbda-f761-7b61-8f02-7b86da122eb1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_019ecbda-f761-734f-ac4b-0b7f48968ea1" 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_npo_SegmentReconciliationAdjustingItemsAbstract_019ecbda-f761-7639-bb84-eb63c0cef340" xlink:to="loc_us-gaap_DepreciationAndAmortization_019ecbda-f761-734f-ac4b-0b7f48968ea1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization_019ecbda-f761-7292-855f-5dcc9354baf5" xlink:href="npo-20260630.xsd#npo_AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f6b8-7847-8a21-7aa2d9599a81" xlink:to="loc_npo_AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization_019ecbda-f761-7292-855f-5dcc9354baf5" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofReconciliationofIncomeFromContinuingOperationsBeforeIncomeTaxestoAdjustedSegmentEBITDADetails" xlink:type="simple" xlink:href="npo-20260630.xsd#BusinessSegmentInformationScheduleofReconciliationofIncomeFromContinuingOperationsBeforeIncomeTaxestoAdjustedSegmentEBITDADetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofReconciliationofIncomeFromContinuingOperationsBeforeIncomeTaxestoAdjustedSegmentEBITDADetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" 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_019ecbda-f761-7410-a5f6-87cd3a95f4e7" 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_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ecbda-f761-7410-a5f6-87cd3a95f4e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ecbda-f761-72ba-8223-9c64cfc48e98" 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_019ecbda-f761-7410-a5f6-87cd3a95f4e7" xlink:to="loc_srt_ConsolidationItemsAxis_019ecbda-f761-72ba-8223-9c64cfc48e98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f761-72ba-8223-9c64cfc48e98_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_019ecbda-f761-72ba-8223-9c64cfc48e98" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f761-72ba-8223-9c64cfc48e98_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f761-7739-9b57-475a87cdb90e" 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_019ecbda-f761-72ba-8223-9c64cfc48e98" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f761-7739-9b57-475a87cdb90e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_019ecbda-f761-7e75-919a-e82ed9902006" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MaterialReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ecbda-f761-7739-9b57-475a87cdb90e" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_019ecbda-f761-7e75-919a-e82ed9902006" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019ecbda-f761-79d5-a2d5-46e3937fc011" 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_019ecbda-f761-7739-9b57-475a87cdb90e" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019ecbda-f761-79d5-a2d5-46e3937fc011" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ecbda-f761-7060-ae13-7ef826b072b9" 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_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ecbda-f761-7060-ae13-7ef826b072b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019ecbda-f761-7768-8c89-ddc5e6ddd6c8" 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_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_019ecbda-f761-7768-8c89-ddc5e6ddd6c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_FairValueAdjustmentToAcquisitionDateInventory_019ecbda-f761-7f8f-a520-945e29da9b1f" xlink:href="npo-20260630.xsd#npo_FairValueAdjustmentToAcquisitionDateInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_npo_FairValueAdjustmentToAcquisitionDateInventory_019ecbda-f761-7f8f-a520-945e29da9b1f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_019ecbda-f761-76a5-93b1-61104ad83f18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestructuringCostsAndAssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_us-gaap_RestructuringCostsAndAssetImpairmentCharges_019ecbda-f761-76a5-93b1-61104ad83f18" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_DepreciationDepletionAndAmortizationAllocatedToSegments_019ecbda-f761-73a8-b194-7d47fa7ab3d3" xlink:href="npo-20260630.xsd#npo_DepreciationDepletionAndAmortizationAllocatedToSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_npo_DepreciationDepletionAndAmortizationAllocatedToSegments_019ecbda-f761-73a8-b194-7d47fa7ab3d3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019ecbda-f761-70da-bba9-9d90a11ba8ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019ecbda-f761-70da-bba9-9d90a11ba8ec" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019ecbda-f761-77fb-8d83-3411924f9f67" 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_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019ecbda-f761-77fb-8d83-3411924f9f67" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019ecbda-f761-7a1b-82ec-c62b1cc9ed75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019ecbda-f761-7a1b-82ec-c62b1cc9ed75" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization_019ecbda-f761-7889-b913-9602340030c0" xlink:href="npo-20260630.xsd#npo_AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-7039-ae28-8d0ea8f3c82c" xlink:to="loc_npo_AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization_019ecbda-f761-7889-b913-9602340030c0" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofNetSalesbyGeographicalAreaDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#BusinessSegmentInformationScheduleofNetSalesbyGeographicalAreaDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofNetSalesbyGeographicalAreaDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-746a-91bb-05200cc1d08e" 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_019ecbda-f761-7d19-b621-55f91df6dd06" 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_019ecbda-f761-746a-91bb-05200cc1d08e" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ecbda-f761-7d19-b621-55f91df6dd06" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019ecbda-f761-7afa-a30f-b19c733f095c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ecbda-f761-7d19-b621-55f91df6dd06" xlink:to="loc_srt_StatementGeographicalAxis_019ecbda-f761-7afa-a30f-b19c733f095c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ecbda-f761-7afa-a30f-b19c733f095c_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019ecbda-f761-7afa-a30f-b19c733f095c" xlink:to="loc_srt_SegmentGeographicalDomain_019ecbda-f761-7afa-a30f-b19c733f095c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ecbda-f761-793e-bb31-b923200941b4" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019ecbda-f761-7afa-a30f-b19c733f095c" xlink:to="loc_srt_SegmentGeographicalDomain_019ecbda-f761-793e-bb31-b923200941b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019ecbda-f761-79df-b8c7-720dd06fb056" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ecbda-f761-793e-bb31-b923200941b4" xlink:to="loc_country_US_019ecbda-f761-79df-b8c7-720dd06fb056" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_019ecbda-f761-7031-9653-5228ed847dd2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ecbda-f761-793e-bb31-b923200941b4" xlink:to="loc_srt_AsiaPacificMember_019ecbda-f761-7031-9653-5228ed847dd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_019ecbda-f761-7aac-9008-96c4747f187a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ecbda-f761-793e-bb31-b923200941b4" xlink:to="loc_srt_EuropeMember_019ecbda-f761-7aac-9008-96c4747f187a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_OtherForeignMember_019ecbda-f761-7620-95e8-1f17c52b16ff" xlink:href="npo-20260630.xsd#npo_OtherForeignMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ecbda-f761-793e-bb31-b923200941b4" xlink:to="loc_npo_OtherForeignMember_019ecbda-f761-7620-95e8-1f17c52b16ff" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019ecbda-f761-7e27-b5fc-d35e63c2ce90" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ecbda-f761-746a-91bb-05200cc1d08e" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019ecbda-f761-7e27-b5fc-d35e63c2ce90" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofThirdPartySalesbyMajorEndMarketDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#BusinessSegmentInformationScheduleofThirdPartySalesbyMajorEndMarketDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofThirdPartySalesbyMajorEndMarketDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019ecbda-f761-7896-864d-98891f0d4373" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019ecbda-f761-784b-a399-cf9ea39f5b0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ecbda-f761-7896-864d-98891f0d4373" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019ecbda-f761-784b-a399-cf9ea39f5b0e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019ecbda-f761-776e-bf4e-cb6d854133e4" 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_DisaggregationOfRevenueTable_019ecbda-f761-784b-a399-cf9ea39f5b0e" xlink:to="loc_srt_ProductOrServiceAxis_019ecbda-f761-776e-bf4e-cb6d854133e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ecbda-f761-776e-bf4e-cb6d854133e4_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_019ecbda-f761-776e-bf4e-cb6d854133e4" xlink:to="loc_srt_ProductsAndServicesDomain_019ecbda-f761-776e-bf4e-cb6d854133e4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" 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_019ecbda-f761-776e-bf4e-cb6d854133e4" xlink:to="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AerospaceMember_019ecbda-f761-752f-8abd-2912b483a1a8" xlink:href="npo-20260630.xsd#npo_AerospaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:to="loc_npo_AerospaceMember_019ecbda-f761-752f-8abd-2912b483a1a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_CommercialVehicleMember_019ecbda-f761-711e-af49-f126cb80e16b" xlink:href="npo-20260630.xsd#npo_CommercialVehicleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:to="loc_npo_CommercialVehicleMember_019ecbda-f761-711e-af49-f126cb80e16b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_FoodandPharmaceuticalMember_019ecbda-f761-7f41-a9a8-a703948e1468" xlink:href="npo-20260630.xsd#npo_FoodandPharmaceuticalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:to="loc_npo_FoodandPharmaceuticalMember_019ecbda-f761-7f41-a9a8-a703948e1468" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_GeneralIndustrialMember_019ecbda-f761-7f63-bc14-deb118fabc95" xlink:href="npo-20260630.xsd#npo_GeneralIndustrialMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:to="loc_npo_GeneralIndustrialMember_019ecbda-f761-7f63-bc14-deb118fabc95" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_OilandGasMarketMember_019ecbda-f761-7e49-bbb3-51b53bc2bf5c" xlink:href="npo-20260630.xsd#npo_OilandGasMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:to="loc_npo_OilandGasMarketMember_019ecbda-f761-7e49-bbb3-51b53bc2bf5c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_PowerGenerationMember_019ecbda-f761-7e01-88a3-e33cd4f964b7" xlink:href="npo-20260630.xsd#npo_PowerGenerationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:to="loc_npo_PowerGenerationMember_019ecbda-f761-7e01-88a3-e33cd4f964b7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SemiconductorsMember_019ecbda-f761-7f19-801e-552bf1e93a1b" xlink:href="npo-20260630.xsd#npo_SemiconductorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019ecbda-f761-7ecd-96ba-a09cf9589ee3" xlink:to="loc_npo_SemiconductorsMember_019ecbda-f761-7f19-801e-552bf1e93a1b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f761-7050-b98a-cd181bf4fad0" 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_DisaggregationOfRevenueTable_019ecbda-f761-784b-a399-cf9ea39f5b0e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f761-7050-b98a-cd181bf4fad0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f761-7050-b98a-cd181bf4fad0_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_019ecbda-f761-7050-b98a-cd181bf4fad0" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f761-7050-b98a-cd181bf4fad0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f761-77ae-876e-314cdc044f83" 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_019ecbda-f761-7050-b98a-cd181bf4fad0" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f761-77ae-876e-314cdc044f83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f761-759b-9026-e6769690a768" xlink:href="npo-20260630.xsd#npo_SealingTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f761-77ae-876e-314cdc044f83" xlink:to="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f761-759b-9026-e6769690a768" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f761-7e79-823f-6bcbffd9e2c7" xlink:href="npo-20260630.xsd#npo_AdvancedSurfaceTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f761-77ae-876e-314cdc044f83" xlink:to="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f761-7e79-823f-6bcbffd9e2c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019ecbda-f761-7146-8bc9-c7ed73449dc5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ecbda-f761-7896-864d-98891f0d4373" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019ecbda-f761-7146-8bc9-c7ed73449dc5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofSegmentRelatedCapitalExpenditureDepreciationandAmortizationonthoseExpendituresDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#BusinessSegmentInformationScheduleofSegmentRelatedCapitalExpenditureDepreciationandAmortizationonthoseExpendituresDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofSegmentRelatedCapitalExpenditureDepreciationandAmortizationonthoseExpendituresDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ecbda-f761-715c-a882-a2c9d71e1fed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7234-abbd-3c0af3e06c0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ecbda-f761-715c-a882-a2c9d71e1fed" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7234-abbd-3c0af3e06c0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ecbda-f761-72c3-b90d-1fd565e9c1c3" 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_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7234-abbd-3c0af3e06c0d" xlink:to="loc_srt_ConsolidationItemsAxis_019ecbda-f761-72c3-b90d-1fd565e9c1c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f761-72c3-b90d-1fd565e9c1c3_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_019ecbda-f761-72c3-b90d-1fd565e9c1c3" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f761-72c3-b90d-1fd565e9c1c3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f761-7622-8ebb-05aeda6c8740" 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_019ecbda-f761-72c3-b90d-1fd565e9c1c3" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f761-7622-8ebb-05aeda6c8740" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ecbda-f761-79c6-83df-12b5d55d528e" 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_019ecbda-f761-7622-8ebb-05aeda6c8740" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ecbda-f761-79c6-83df-12b5d55d528e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f761-7be5-a62b-5bb814f3713d" 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_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7234-abbd-3c0af3e06c0d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f761-7be5-a62b-5bb814f3713d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f761-7be5-a62b-5bb814f3713d_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_019ecbda-f761-7be5-a62b-5bb814f3713d" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f761-7be5-a62b-5bb814f3713d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f761-76e6-b5e0-60b07110ae7f" 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_019ecbda-f761-7be5-a62b-5bb814f3713d" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f761-76e6-b5e0-60b07110ae7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f761-76f1-bfb0-05726d427bb6" xlink:href="npo-20260630.xsd#npo_SealingTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f761-76e6-b5e0-60b07110ae7f" xlink:to="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f761-76f1-bfb0-05726d427bb6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f761-75ca-880d-b695b66c3331" xlink:href="npo-20260630.xsd#npo_AdvancedSurfaceTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f761-76e6-b5e0-60b07110ae7f" xlink:to="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f761-75ca-880d-b695b66c3331" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019ecbda-f761-7fa6-8028-83e0e505720f" 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_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ecbda-f761-715c-a882-a2c9d71e1fed" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019ecbda-f761-7fa6-8028-83e0e505720f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019ecbda-f761-7835-a0c8-5e323b75fb70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ecbda-f761-715c-a882-a2c9d71e1fed" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019ecbda-f761-7835-a0c8-5e323b75fb70" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofAssetsbySegmentDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#BusinessSegmentInformationScheduleofAssetsbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/BusinessSegmentInformationScheduleofAssetsbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ecbda-f761-7c09-baf9-4698c6b221cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7e22-bcd7-2c2ea686cda0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ecbda-f761-7c09-baf9-4698c6b221cc" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7e22-bcd7-2c2ea686cda0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ecbda-f761-79c9-8500-2a777c0c96e0" 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_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7e22-bcd7-2c2ea686cda0" xlink:to="loc_srt_ConsolidationItemsAxis_019ecbda-f761-79c9-8500-2a777c0c96e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f761-79c9-8500-2a777c0c96e0_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_019ecbda-f761-79c9-8500-2a777c0c96e0" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f761-79c9-8500-2a777c0c96e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ecbda-f761-7dd8-b491-950155d663b1" 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_019ecbda-f761-79c9-8500-2a777c0c96e0" xlink:to="loc_srt_ConsolidationItemsDomain_019ecbda-f761-7dd8-b491-950155d663b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ecbda-f761-79e5-b266-a90364e8e971" 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_019ecbda-f761-7dd8-b491-950155d663b1" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ecbda-f761-79e5-b266-a90364e8e971" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019ecbda-f761-72b7-9ca9-2b9f44a2b6ad" 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_019ecbda-f761-7dd8-b491-950155d663b1" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019ecbda-f761-72b7-9ca9-2b9f44a2b6ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f761-76e8-bcce-04fb26b8c2a8" 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_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019ecbda-f761-7e22-bcd7-2c2ea686cda0" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ecbda-f761-76e8-bcce-04fb26b8c2a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f761-76e8-bcce-04fb26b8c2a8_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_019ecbda-f761-76e8-bcce-04fb26b8c2a8" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f761-76e8-bcce-04fb26b8c2a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ecbda-f761-7f80-a019-dd1bdae78da8" 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_019ecbda-f761-76e8-bcce-04fb26b8c2a8" xlink:to="loc_us-gaap_SegmentDomain_019ecbda-f761-7f80-a019-dd1bdae78da8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f761-7872-ac24-e55e933647cf" xlink:href="npo-20260630.xsd#npo_SealingTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f761-7f80-a019-dd1bdae78da8" xlink:to="loc_npo_SealingTechnologiesSegmentMember_019ecbda-f761-7872-ac24-e55e933647cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f761-7dcf-9f84-f363e768da4c" xlink:href="npo-20260630.xsd#npo_AdvancedSurfaceTechnologiesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ecbda-f761-7f80-a019-dd1bdae78da8" xlink:to="loc_npo_AdvancedSurfaceTechnologiesSegmentMember_019ecbda-f761-7dcf-9f84-f363e768da4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019ecbda-f761-7c3c-ab11-bc3ad9a265f6" 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_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019ecbda-f761-7c09-baf9-4698c6b221cc" xlink:to="loc_us-gaap_Assets_019ecbda-f761-7c3c-ab11-bc3ad9a265f6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/DerivativesandHedgingDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#DerivativesandHedgingDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/DerivativesandHedgingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_019ecbda-f761-7abf-84f4-8f59a8d3b316" 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_019ecbda-f761-7465-8b89-b8c3959d4bbe" 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_019ecbda-f761-7abf-84f4-8f59a8d3b316" xlink:to="loc_us-gaap_DerivativeTable_019ecbda-f761-7465-8b89-b8c3959d4bbe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019ecbda-f761-7972-b3e3-5a72e60fd113" 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_019ecbda-f761-7465-8b89-b8c3959d4bbe" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019ecbda-f761-7972-b3e3-5a72e60fd113" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ecbda-f761-7972-b3e3-5a72e60fd113_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_019ecbda-f761-7972-b3e3-5a72e60fd113" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ecbda-f761-7972-b3e3-5a72e60fd113_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ecbda-f761-741e-a42a-a00e7e46de07" 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_019ecbda-f761-7972-b3e3-5a72e60fd113" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ecbda-f761-741e-a42a-a00e7e46de07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_019ecbda-f761-7aba-b5b4-ba88a4963a2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ecbda-f761-741e-a42a-a00e7e46de07" xlink:to="loc_us-gaap_CurrencySwapMember_019ecbda-f761-7aba-b5b4-ba88a4963a2d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_019ecbda-f761-7285-af0a-f24d2c1b4c1c" 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_019ecbda-f761-741e-a42a-a00e7e46de07" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_019ecbda-f761-7285-af0a-f24d2c1b4c1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForwardContractsMember_019ecbda-f761-7397-90bb-50c21c4c2444" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForwardContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ecbda-f761-741e-a42a-a00e7e46de07" xlink:to="loc_us-gaap_ForwardContractsMember_019ecbda-f761-7397-90bb-50c21c4c2444" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAmountOfHedgedItem_019ecbda-f761-742b-8d36-8312b7deb688" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAmountOfHedgedItem"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ecbda-f761-7abf-84f4-8f59a8d3b316" xlink:to="loc_us-gaap_DerivativeAmountOfHedgedItem_019ecbda-f761-742b-8d36-8312b7deb688" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossAfterTax_019ecbda-f761-7610-bf9a-b9ac50b7d63d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ecbda-f761-7abf-84f4-8f59a8d3b316" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossAfterTax_019ecbda-f761-7610-bf9a-b9ac50b7d63d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_019ecbda-f761-7a5f-9fea-d444f95d5c6e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ecbda-f761-7abf-84f4-8f59a8d3b316" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_019ecbda-f761-7a5f-9fea-d444f95d5c6e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_019ecbda-f761-7e49-b397-07d8e446ddc5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ecbda-f761-7abf-84f4-8f59a8d3b316" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_019ecbda-f761-7e49-b397-07d8e446ddc5" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/AccumulatedOtherComprehensiveIncomeLossScheduleofChangesinAccumulatedOtherComprehensiveIncomeLossbyComponentDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#AccumulatedOtherComprehensiveIncomeLossScheduleofChangesinAccumulatedOtherComprehensiveIncomeLossbyComponentDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/AccumulatedOtherComprehensiveIncomeLossScheduleofChangesinAccumulatedOtherComprehensiveIncomeLossbyComponentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019ecbda-f761-7f5a-8cf2-e39176e39d53" 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_019ecbda-f761-797f-afb2-d80571d4eab7" 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_019ecbda-f761-7f5a-8cf2-e39176e39d53" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019ecbda-f761-797f-afb2-d80571d4eab7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019ecbda-f761-7dde-9671-266966c48035" 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_019ecbda-f761-797f-afb2-d80571d4eab7" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019ecbda-f761-7dde-9671-266966c48035" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ecbda-f761-7dde-9671-266966c48035_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_019ecbda-f761-7dde-9671-266966c48035" xlink:to="loc_us-gaap_EquityComponentDomain_019ecbda-f761-7dde-9671-266966c48035_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ecbda-f761-73ce-9b87-1bbf65141705" 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_019ecbda-f761-7dde-9671-266966c48035" xlink:to="loc_us-gaap_EquityComponentDomain_019ecbda-f761-73ce-9b87-1bbf65141705" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ecbda-f761-7be8-bbd7-509833a3a788" 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_019ecbda-f761-73ce-9b87-1bbf65141705" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ecbda-f761-7be8-bbd7-509833a3a788" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019ecbda-f761-7424-9d72-5e6a29d88143" 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_019ecbda-f761-7be8-bbd7-509833a3a788" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019ecbda-f761-7424-9d72-5e6a29d88143" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019ecbda-f761-71d2-a9ce-b9ba242cf444" 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_019ecbda-f761-7be8-bbd7-509833a3a788" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019ecbda-f761-71d2-a9ce-b9ba242cf444" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ecbda-f761-7028-94aa-1ffb0e4cb687" 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_019ecbda-f761-7f5a-8cf2-e39176e39d53" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ecbda-f761-7028-94aa-1ffb0e4cb687" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ecbda-f761-74f3-8c54-b299b66f266f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ecbda-f761-7028-94aa-1ffb0e4cb687" xlink:to="loc_us-gaap_StockholdersEquity_019ecbda-f761-74f3-8c54-b299b66f266f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019ecbda-f761-74de-9011-badea6599e2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ecbda-f761-7028-94aa-1ffb0e4cb687" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019ecbda-f761-74de-9011-badea6599e2b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_019ecbda-f761-7915-b4be-ce7311839527" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019ecbda-f761-7028-94aa-1ffb0e4cb687" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_019ecbda-f761-7915-b4be-ce7311839527" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ecbda-f761-7894-a033-22050e722f04" 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_AOCIAttributableToParentNetOfTaxRollForward_019ecbda-f761-7028-94aa-1ffb0e4cb687" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ecbda-f761-7894-a033-22050e722f04" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ecbda-f761-7316-b4db-a63cf20f6f96" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.enproindustries.com/role/CommitmentsandContingenciesAdditionalInformationDetails" xlink:type="simple" xlink:href="npo-20260630.xsd#CommitmentsandContingenciesAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://www.enproindustries.com/role/CommitmentsandContingenciesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SiteContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SiteContingencyTable_019ecbda-f761-783e-a18c-6d14cc2e49dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SiteContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_SiteContingencyTable_019ecbda-f761-783e-a18c-6d14cc2e49dc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ecbda-f761-702c-af89-476e093349fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_019ecbda-f761-783e-a18c-6d14cc2e49dc" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ecbda-f761-702c-af89-476e093349fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019ecbda-f761-702c-af89-476e093349fe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ecbda-f761-702c-af89-476e093349fe" xlink:to="loc_us-gaap_RelatedPartyDomain_019ecbda-f761-702c-af89-476e093349fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019ecbda-f761-79f8-a4b5-3d79e3e4caea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019ecbda-f761-702c-af89-476e093349fe" xlink:to="loc_us-gaap_RelatedPartyDomain_019ecbda-f761-79f8-a4b5-3d79e3e4caea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019ecbda-f761-773c-b820-6708ce8b48c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019ecbda-f761-79f8-a4b5-3d79e3e4caea" xlink:to="loc_us-gaap_RelatedPartyMember_019ecbda-f761-773c-b820-6708ce8b48c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019ecbda-f761-7ab2-827a-2a658e29e34b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_019ecbda-f761-783e-a18c-6d14cc2e49dc" xlink:to="loc_dei_LegalEntityAxis_019ecbda-f761-7ab2-827a-2a658e29e34b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019ecbda-f761-7ab2-827a-2a658e29e34b_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019ecbda-f761-7ab2-827a-2a658e29e34b" xlink:to="loc_dei_EntityDomain_019ecbda-f761-7ab2-827a-2a658e29e34b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019ecbda-f761-7266-bfc0-4c6c8f4dfede" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019ecbda-f761-7ab2-827a-2a658e29e34b" xlink:to="loc_dei_EntityDomain_019ecbda-f761-7266-bfc0-4c6c8f4dfede" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_CrucibleSteelCorporationMember_019ecbda-f761-7fc7-b0bc-b2a750c8a6d9" xlink:href="npo-20260630.xsd#npo_CrucibleSteelCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019ecbda-f761-7266-bfc0-4c6c8f4dfede" xlink:to="loc_npo_CrucibleSteelCorporationMember_019ecbda-f761-7fc7-b0bc-b2a750c8a6d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalRemediationSiteAxis_019ecbda-f761-79de-aeae-3baeb3854ef1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EnvironmentalRemediationSiteAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SiteContingencyTable_019ecbda-f761-783e-a18c-6d14cc2e49dc" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteAxis_019ecbda-f761-79de-aeae-3baeb3854ef1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-79de-aeae-3baeb3854ef1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EnvironmentalRemediationSiteDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteAxis_019ecbda-f761-79de-aeae-3baeb3854ef1" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-79de-aeae-3baeb3854ef1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EnvironmentalRemediationSiteDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteAxis_019ecbda-f761-79de-aeae-3baeb3854ef1" xlink:to="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LowerPassaicRiverStudyAreaMember_019ecbda-f761-7b36-83a3-f7d45117edde" xlink:href="npo-20260630.xsd#npo_LowerPassaicRiverStudyAreaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_LowerPassaicRiverStudyAreaMember_019ecbda-f761-7b36-83a3-f7d45117edde" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_UpperNineMilesOfTheRiverMember_019ecbda-f761-767d-8380-fe708ed827f3" xlink:href="npo-20260630.xsd#npo_UpperNineMilesOfTheRiverMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_UpperNineMilesOfTheRiverMember_019ecbda-f761-767d-8380-fe708ed827f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LowerPassaicRiverStudyAreaLowerEightMilesMember_019ecbda-f761-74c1-a7e4-e4bccce9dd96" xlink:href="npo-20260630.xsd#npo_LowerPassaicRiverStudyAreaLowerEightMilesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_LowerPassaicRiverStudyAreaLowerEightMilesMember_019ecbda-f761-74c1-a7e4-e4bccce9dd96" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LowerPassaicRiverStudyAreaOU4RecoveryOfCostsMember_019ecbda-f761-7bb5-a71b-c8464d43b18f" xlink:href="npo-20260630.xsd#npo_LowerPassaicRiverStudyAreaOU4RecoveryOfCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_LowerPassaicRiverStudyAreaOU4RecoveryOfCostsMember_019ecbda-f761-7bb5-a71b-c8464d43b18f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_ArizonaUraniumMinesMember_019ecbda-f761-72a2-b1e1-2551a554e26a" xlink:href="npo-20260630.xsd#npo_ArizonaUraniumMinesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_ArizonaUraniumMinesMember_019ecbda-f761-72a2-b1e1-2551a554e26a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_ThorofareNewJerseyMember_019ecbda-f761-74e6-a209-5bc6b9da11d4" xlink:href="npo-20260630.xsd#npo_ThorofareNewJerseyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_ThorofareNewJerseyMember_019ecbda-f761-74e6-a209-5bc6b9da11d4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_GGBIndustrialSiteRemediationActISRAInvestigationAndCleanupMember_019ecbda-f761-719a-bc78-4daa0952577e" xlink:href="npo-20260630.xsd#npo_GGBIndustrialSiteRemediationActISRAInvestigationAndCleanupMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_GGBIndustrialSiteRemediationActISRAInvestigationAndCleanupMember_019ecbda-f761-719a-bc78-4daa0952577e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_WaterValleyMississippiMember_019ecbda-f761-7457-b03b-d4f27d0f3d9b" xlink:href="npo-20260630.xsd#npo_WaterValleyMississippiMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_WaterValleyMississippiMember_019ecbda-f761-7457-b03b-d4f27d0f3d9b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_WaterValleyFacilityMember_019fa25e-e17c-7d29-9025-669557e5e7e7" xlink:href="npo-20260630.xsd#npo_WaterValleyFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_WaterValleyFacilityMember_019fa25e-e17c-7d29-9025-669557e5e7e7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_PineBluffMember_019ecbda-f761-77ea-b63a-d9dd1dd68910" xlink:href="npo-20260630.xsd#npo_PineBluffMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EnvironmentalRemediationSiteDomain_019ecbda-f761-70be-b78d-ef382e77c2eb" xlink:to="loc_npo_PineBluffMember_019ecbda-f761-77ea-b63a-d9dd1dd68910" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019ecbda-f761-7ade-b914-8db0da6b1e44" 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_SiteContingencyTable_019ecbda-f761-783e-a18c-6d14cc2e49dc" xlink:to="loc_srt_RangeAxis_019ecbda-f761-7ade-b914-8db0da6b1e44" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ecbda-f761-7ade-b914-8db0da6b1e44_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_019ecbda-f761-7ade-b914-8db0da6b1e44" xlink:to="loc_srt_RangeMember_019ecbda-f761-7ade-b914-8db0da6b1e44_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ecbda-f761-7569-8cca-8519e3c222f8" 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_019ecbda-f761-7ade-b914-8db0da6b1e44" xlink:to="loc_srt_RangeMember_019ecbda-f761-7569-8cca-8519e3c222f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019ecbda-f761-7430-9c4a-e76ca38a76b9" 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_019ecbda-f761-7569-8cca-8519e3c222f8" xlink:to="loc_srt_MinimumMember_019ecbda-f761-7430-9c4a-e76ca38a76b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivities_019ecbda-f761-7fb1-ac5f-95b20e0edab5" xlink:href="npo-20260630.xsd#npo_SiteContingencyNumberOfSitesSubjectToRemediationActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivities_019ecbda-f761-7fb1-ac5f-95b20e0edab5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesCostLessThan500K_019ecbda-f761-763c-b3d9-1bd69a91fb59" xlink:href="npo-20260630.xsd#npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesCostLessThan500K"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesCostLessThan500K_019ecbda-f761-763c-b3d9-1bd69a91fb59" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencySitesSubjectToRemediationActivitiesCostPerSiteMaximumExpectedCost_019ecbda-f761-7921-8a45-ba57088b66ee" xlink:href="npo-20260630.xsd#npo_SiteContingencySitesSubjectToRemediationActivitiesCostPerSiteMaximumExpectedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencySitesSubjectToRemediationActivitiesCostPerSiteMaximumExpectedCost_019ecbda-f761-7921-8a45-ba57088b66ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesOneOrMoreSubsidiariesConductedBusinessButNoLongerDo_019ecbda-f761-7a6f-8678-f49f7ddb3913" xlink:href="npo-20260630.xsd#npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesOneOrMoreSubsidiariesConductedBusinessButNoLongerDo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesOneOrMoreSubsidiariesConductedBusinessButNoLongerDo_019ecbda-f761-7a6f-8678-f49f7ddb3913" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingencies_019ecbda-f761-7611-9b63-e3ab3a5ca4b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccrualForEnvironmentalLossContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingencies_019ecbda-f761-7611-9b63-e3ab3a5ca4b2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AccruedEnvironmentalLossContingenciesCurrentGross_019ecbda-f761-701a-865d-ff38027231dd" xlink:href="npo-20260630.xsd#npo_AccruedEnvironmentalLossContingenciesCurrentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_AccruedEnvironmentalLossContingenciesCurrentGross_019ecbda-f761-701a-865d-ff38027231dd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_PortionOfSiteSubjectToRemediation_019ecbda-f761-76cf-aae9-2fd184f67042" xlink:href="npo-20260630.xsd#npo_PortionOfSiteSubjectToRemediation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_PortionOfSiteSubjectToRemediation_019ecbda-f761-76cf-aae9-2fd184f67042" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencyNumberOfOperatingUnits_019ecbda-f761-7392-8b5c-7638deecbc5d" xlink:href="npo-20260630.xsd#npo_SiteContingencyNumberOfOperatingUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencyNumberOfOperatingUnits_019ecbda-f761-7392-8b5c-7638deecbc5d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SiteContingencyLossExposureInExcessOfAccrualBestEstimate_019ecbda-f761-7702-a46b-526fbc185ab8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SiteContingencyLossExposureInExcessOfAccrualBestEstimate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_SiteContingencyLossExposureInExcessOfAccrualBestEstimate_019ecbda-f761-7702-a46b-526fbc185ab8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LossContingencyNumberOfPotentiallyResponsibleParties_019f1210-9bf3-7b83-bb10-9b6946fb2bcc" xlink:href="npo-20260630.xsd#npo_LossContingencyNumberOfPotentiallyResponsibleParties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_LossContingencyNumberOfPotentiallyResponsibleParties_019f1210-9bf3-7b83-bb10-9b6946fb2bcc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualPayments_019ecbda-f761-7fd9-9cc5-5c30833b8e6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyAccrualPayments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_LossContingencyAccrualPayments_019ecbda-f761-7fd9-9cc5-5c30833b8e6f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencyNumberOfOtherPotentiallyResponsibleParties_019ecbda-f761-75d1-9552-35a229bb3d7b" xlink:href="npo-20260630.xsd#npo_SiteContingencyNumberOfOtherPotentiallyResponsibleParties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencyNumberOfOtherPotentiallyResponsibleParties_019ecbda-f761-75d1-9552-35a229bb3d7b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SiteContingencyLossExposureNotAccruedBestEstimate_019ecbda-f761-73a5-8d83-2f1e5e524f7e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SiteContingencyLossExposureNotAccruedBestEstimate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_SiteContingencyLossExposureNotAccruedBestEstimate_019ecbda-f761-73a5-8d83-2f1e5e524f7e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_InvestigativeSitesNoticeFromTheEPA_019ecbda-f761-79d7-ab9e-e90e95203a0c" xlink:href="npo-20260630.xsd#npo_InvestigativeSitesNoticeFromTheEPA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_InvestigativeSitesNoticeFromTheEPA_019ecbda-f761-79d7-ab9e-e90e95203a0c" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_NumberOfPriorityMines_019ecbda-f761-715e-868d-8134315a7777" xlink:href="npo-20260630.xsd#npo_NumberOfPriorityMines"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_NumberOfPriorityMines_019ecbda-f761-715e-868d-8134315a7777" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_NumberOfNonPriorityMines_019ecbda-f761-7b52-b1df-4368b6ae631d" xlink:href="npo-20260630.xsd#npo_NumberOfNonPriorityMines"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_NumberOfNonPriorityMines_019ecbda-f761-7b52-b1df-4368b6ae631d" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPeriodIncreaseDecrease_019fa23b-a457-7617-88e7-a898067a51f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccrualForEnvironmentalLossContingenciesPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingenciesPeriodIncreaseDecrease_019fa23b-a457-7617-88e7-a898067a51f6" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_AmountOfExpectedReimbursementByTheGovernmentPercent_019ecbda-f761-7ea6-9572-33a7fa268767" xlink:href="npo-20260630.xsd#npo_AmountOfExpectedReimbursementByTheGovernmentPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_AmountOfExpectedReimbursementByTheGovernmentPercent_019ecbda-f761-7ea6-9572-33a7fa268767" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesReceivable_019fafd1-abbf-73cf-9a1f-39cc0f06564c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RecordedThirdPartyEnvironmentalRecoveriesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesReceivable_019fafd1-abbf-73cf-9a1f-39cc0f06564c" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_RecordedThirdPartyEnvironmentalRecoveriesReceivableIncreaseDecreaseDuringPeriod_019fafd5-cad6-71a4-a581-edc60d1045b3" xlink:href="npo-20260630.xsd#npo_RecordedThirdPartyEnvironmentalRecoveriesReceivableIncreaseDecreaseDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_RecordedThirdPartyEnvironmentalRecoveriesReceivableIncreaseDecreaseDuringPeriod_019fafd5-cad6-71a4-a581-edc60d1045b3" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_NumberOfFacilities_019ecbda-f761-7491-96a2-abcb7e51d18f" xlink:href="npo-20260630.xsd#npo_NumberOfFacilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_NumberOfFacilities_019ecbda-f761-7491-96a2-abcb7e51d18f" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesActiveOperations_019ecbda-f761-7ab7-9b18-d0965f83a42a" xlink:href="npo-20260630.xsd#npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesActiveOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesActiveOperations_019ecbda-f761-7ab7-9b18-d0965f83a42a" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_019ecbda-f761-7e31-af88-737a30490ddc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_019ecbda-f761-7e31-af88-737a30490ddc" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_019ecbda-f761-701f-ac5b-66c4bd1902b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNewClaimsFiledNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_019ecbda-f761-701f-ac5b-66c4bd1902b4" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNumberOfPlaintiffs_019fa252-c387-70f4-b3ff-5dfa37611382" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNumberOfPlaintiffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_LossContingencyNumberOfPlaintiffs_019fa252-c387-70f4-b3ff-5dfa37611382" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LossContingencyNewClaimsFiledNumberNotNamedAsDefendants_019ecbda-f761-7912-a367-3e5b05604af7" xlink:href="npo-20260630.xsd#npo_LossContingencyNewClaimsFiledNumberNotNamedAsDefendants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_LossContingencyNewClaimsFiledNumberNotNamedAsDefendants_019ecbda-f761-7912-a367-3e5b05604af7" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LossContingencyNumberOfPlaintiffsNotNamedAsDefendant_019ecbda-f761-7c8a-bcb4-48b784e5cb06" xlink:href="npo-20260630.xsd#npo_LossContingencyNumberOfPlaintiffsNotNamedAsDefendant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_LossContingencyNumberOfPlaintiffsNotNamedAsDefendant_019ecbda-f761-7c8a-bcb4-48b784e5cb06" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LossContingencyNumberOfDefendantsNamedInLitigationManufacturer_019ecbda-f761-7324-a0d4-c983bb5cfce9" xlink:href="npo-20260630.xsd#npo_LossContingencyNumberOfDefendantsNamedInLitigationManufacturer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_LossContingencyNumberOfDefendantsNamedInLitigationManufacturer_019ecbda-f761-7324-a0d4-c983bb5cfce9" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LossContingencyNumberOfDefendantsNamedInLitigationIndividualConsultant_019ecbda-f761-7acf-a92c-68288c228d46" xlink:href="npo-20260630.xsd#npo_LossContingencyNumberOfDefendantsNamedInLitigationIndividualConsultant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_LossContingencyNumberOfDefendantsNamedInLitigationIndividualConsultant_019ecbda-f761-7acf-a92c-68288c228d46" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LossContingencyNumberOfDefendantsNamedInLitigationConsultingAndConstructionFirms_019ecbda-f761-7d4b-9957-600de45199dd" xlink:href="npo-20260630.xsd#npo_LossContingencyNumberOfDefendantsNamedInLitigationConsultingAndConstructionFirms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_LossContingencyNumberOfDefendantsNamedInLitigationConsultingAndConstructionFirms_019ecbda-f761-7d4b-9957-600de45199dd" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_LossContingencyNumberOfClaimsNamedAsDefendant_019ecbda-f761-78c8-9254-66610c6e9585" xlink:href="npo-20260630.xsd#npo_LossContingencyNumberOfClaimsNamedAsDefendant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_LossContingencyNumberOfClaimsNamedAsDefendant_019ecbda-f761-78c8-9254-66610c6e9585" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_NumberOfClaimants_019ecbda-f761-739a-9e7a-e5831b3793c0" xlink:href="npo-20260630.xsd#npo_NumberOfClaimants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_NumberOfClaimants_019ecbda-f761-739a-9e7a-e5831b3793c0" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesAddition_019ecbda-f761-7bc9-ab54-e1132818b337" xlink:href="npo-20260630.xsd#npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesAddition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_npo_SiteContingencyNumberOfSitesSubjectToRemediationActivitiesAddition_019ecbda-f761-7bc9-ab54-e1132818b337" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019ecbda-f761-7244-9dda-590b1af7d4d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019ecbda-f761-777b-bec2-eea60c3ee07b" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019ecbda-f761-7244-9dda-590b1af7d4d8" xlink:type="arc" order="33"/>
  </link:definitionLink>
</link:linkbase>
