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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:01a03a22-9359-70d6-97fd-8e0979641848,g:28325de1-2d83-4ee1-8190-ce7bb5fc2829-->
<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.applied.com/role/CONDENSEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="ait-20260930.xsd#CONDENSEDSTATEMENTSOFSHAREHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/CONDENSEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_01a03a22-9415-79ee-92c0-9e362a4e2c8b" 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_01a03a22-9415-78cf-9175-88bf67a00051" 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_01a03a22-9415-79ee-92c0-9e362a4e2c8b" xlink:to="loc_us-gaap_StatementTable_01a03a22-9415-78cf-9175-88bf67a00051" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_01a03a22-9415-74b5-8b3d-5af9cceb5e9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a03a22-9415-78cf-9175-88bf67a00051" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_01a03a22-9415-74b5-8b3d-5af9cceb5e9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a03a22-9415-74b5-8b3d-5af9cceb5e9d_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_01a03a22-9415-74b5-8b3d-5af9cceb5e9d" xlink:to="loc_us-gaap_EquityComponentDomain_01a03a22-9415-74b5-8b3d-5af9cceb5e9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a03a22-9415-7eae-a024-71ba82e00aa5" 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_01a03a22-9415-74b5-8b3d-5af9cceb5e9d" xlink:to="loc_us-gaap_EquityComponentDomain_01a03a22-9415-7eae-a024-71ba82e00aa5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_01a03a22-9415-7789-b953-3b17d1364865" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a03a22-9415-7eae-a024-71ba82e00aa5" xlink:to="loc_us-gaap_ParentMember_01a03a22-9415-7789-b953-3b17d1364865" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_01a03a22-9415-7db0-ba72-041e17b4cd40" 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_ParentMember_01a03a22-9415-7789-b953-3b17d1364865" xlink:to="loc_us-gaap_CommonStockMember_01a03a22-9415-7db0-ba72-041e17b4cd40" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_01a03a22-9415-76f6-b993-58b28966163d" 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_ParentMember_01a03a22-9415-7789-b953-3b17d1364865" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_01a03a22-9415-76f6-b993-58b28966163d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_01a03a22-9415-7f2b-a8ca-bdffbdd7004f" 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_ParentMember_01a03a22-9415-7789-b953-3b17d1364865" xlink:to="loc_us-gaap_RetainedEarningsMember_01a03a22-9415-7f2b-a8ca-bdffbdd7004f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_01a03a22-9415-7194-b62d-6eecfbeb057c" 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_ParentMember_01a03a22-9415-7789-b953-3b17d1364865" xlink:to="loc_us-gaap_TreasuryStockCommonMember_01a03a22-9415-7194-b62d-6eecfbeb057c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a03a22-9415-704e-bc10-296211606e41" 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_ParentMember_01a03a22-9415-7789-b953-3b17d1364865" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a03a22-9415-704e-bc10-296211606e41" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a03a22-9415-7d0f-8af3-0e405bb3c090" 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_StatementTable_01a03a22-9415-78cf-9175-88bf67a00051" xlink:to="loc_us-gaap_AwardTypeAxis_01a03a22-9415-7d0f-8af3-0e405bb3c090" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a03a22-9415-7d0f-8af3-0e405bb3c090_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_01a03a22-9415-7d0f-8af3-0e405bb3c090" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a03a22-9415-7d0f-8af3-0e405bb3c090_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a03a22-9415-7cbc-a696-221b21bf0043" 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_01a03a22-9415-7d0f-8af3-0e405bb3c090" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a03a22-9415-7cbc-a696-221b21bf0043" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_StockOptionsAndStockAppreciationRightsMember_01a03a22-9415-7100-9897-d66b4d9e6d50" xlink:href="ait-20260930.xsd#ait_StockOptionsAndStockAppreciationRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a03a22-9415-7cbc-a696-221b21bf0043" xlink:to="loc_ait_StockOptionsAndStockAppreciationRightsMember_01a03a22-9415-7100-9897-d66b4d9e6d50" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_01a03a22-9415-7a7f-892d-76541fcfad9b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a03a22-9415-7cbc-a696-221b21bf0043" xlink:to="loc_us-gaap_PerformanceSharesMember_01a03a22-9415-7a7f-892d-76541fcfad9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_01a03a22-9415-7a1b-90d7-81b734166ab2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a03a22-9415-7cbc-a696-221b21bf0043" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_01a03a22-9415-7a1b-90d7-81b734166ab2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a03a22-9415-79ee-92c0-9e362a4e2c8b" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_01a03a22-9415-725c-8cf5-e7ca0e2bd295" 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_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_01a03a22-9415-725c-8cf5-e7ca0e2bd295" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_01a03a22-9415-70cc-8d65-7ea096ee0d38" 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_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_StockholdersEquity_01a03a22-9415-70cc-8d65-7ea096ee0d38" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a03a22-9415-73e3-84da-061c695419bf" 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_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_NetIncomeLoss_01a03a22-9415-73e3-84da-061c695419bf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a03a22-9415-75bc-9f09-4cf15811cb27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a03a22-9415-75bc-9f09-4cf15811cb27" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_01a03a22-9415-7fda-b97c-ed098d0373bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_01a03a22-9415-7fda-b97c-ed098d0373bb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_01a03a22-9415-7d91-b533-a03824ac3b31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_01a03a22-9415-7d91-b533-a03824ac3b31" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:href="ait-20260930.xsd#ait_TreasurySharesIssuedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_01a03a22-9415-7d86-aef5-2ed04fdc97ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_01a03a22-9415-7d86-aef5-2ed04fdc97ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions_01a03a22-9415-77fd-8153-cd313bb1587d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions_01a03a22-9415-77fd-8153-cd313bb1587d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_01a03a22-9415-7394-845c-497d63b7c34f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_01a03a22-9415-7394-845c-497d63b7c34f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease_01a03a22-9415-7b1a-8e9d-9e79e1a9d57d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_us-gaap_StockholdersEquityPeriodIncreaseDecrease_01a03a22-9415-7b1a-8e9d-9e79e1a9d57d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceSharesExercisesInPeriod_01a03a22-9415-7bf4-bfc1-9886991ff5bc" xlink:href="ait-20260930.xsd#ait_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceSharesExercisesInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_ait_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceSharesExercisesInPeriod_01a03a22-9415-7bf4-bfc1-9886991ff5bc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_01a03a22-9415-7797-99a9-23971352db60" 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_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_01a03a22-9415-7797-99a9-23971352db60" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_01a03a22-9415-7f99-8b9b-86754267a37e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_01a03a22-9415-7f99-8b9b-86754267a37e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_01a03a22-9415-7885-9ce6-5757c5cefc7b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_TreasurySharesIssuedAbstract_01a03a22-9415-714d-870d-e057c0ba48e4" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_01a03a22-9415-7885-9ce6-5757c5cefc7b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_01a03a22-9415-700a-9124-b71e9e9aca5e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_01a03a22-9415-700a-9124-b71e9e9aca5e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOtherShares_01a03a22-9415-70e8-a136-b521b099f928" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityOtherShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_StockholdersEquityOtherShares_01a03a22-9415-70e8-a136-b521b099f928" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_01a03a22-9415-718f-92f6-88dcde328816" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a14151-f87a-7e7d-9642-1cd79fd36457" xlink:to="loc_us-gaap_StockholdersEquityOther_01a03a22-9415-718f-92f6-88dcde328816" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_01a03a22-9415-748b-aaf2-80db7be8cb1d" 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_01a03a22-9415-744d-9118-004d3b9e52d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/REVENUERECOGNITIONScheduleofNetSalesbyReportableSegmentandbyGeographicAreasDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#REVENUERECOGNITIONScheduleofNetSalesbyReportableSegmentandbyGeographicAreasDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/REVENUERECOGNITIONScheduleofNetSalesbyReportableSegmentandbyGeographicAreasDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_01a03a22-9415-76ed-a829-28f56d4864e3" 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_01a03a22-9415-73d0-a48b-aaff0d9af9d3" 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_01a03a22-9415-76ed-a829-28f56d4864e3" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_01a03a22-9415-73d0-a48b-aaff0d9af9d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9415-75f9-b399-883bbcad58c8" 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_01a03a22-9415-73d0-a48b-aaff0d9af9d3" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9415-75f9-b399-883bbcad58c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9415-75f9-b399-883bbcad58c8_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_01a03a22-9415-75f9-b399-883bbcad58c8" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9415-75f9-b399-883bbcad58c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9415-7380-a85b-6c0993a8d1e7" 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_01a03a22-9415-75f9-b399-883bbcad58c8" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9415-7380-a85b-6c0993a8d1e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9415-7462-9fa7-26c7a1d52c08" xlink:href="ait-20260930.xsd#ait_ServiceCenterBasedDistributionSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9415-7380-a85b-6c0993a8d1e7" xlink:to="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9415-7462-9fa7-26c7a1d52c08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9415-73e1-ba49-8c447e0577f6" xlink:href="ait-20260930.xsd#ait_EngineeredSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9415-7380-a85b-6c0993a8d1e7" xlink:to="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9415-73e1-ba49-8c447e0577f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_01a03a22-9415-768f-a4a7-5b8c41ec48c5" 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_DisaggregationOfRevenueTable_01a03a22-9415-73d0-a48b-aaff0d9af9d3" xlink:to="loc_srt_StatementGeographicalAxis_01a03a22-9415-768f-a4a7-5b8c41ec48c5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_01a03a22-9415-768f-a4a7-5b8c41ec48c5_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_01a03a22-9415-768f-a4a7-5b8c41ec48c5" xlink:to="loc_srt_SegmentGeographicalDomain_01a03a22-9415-768f-a4a7-5b8c41ec48c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_01a03a22-9415-7cf7-9bbd-444d008eef46" 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_01a03a22-9415-768f-a4a7-5b8c41ec48c5" xlink:to="loc_srt_SegmentGeographicalDomain_01a03a22-9415-7cf7-9bbd-444d008eef46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_01a03a22-9415-7ccf-82ed-8ea12ba5a4c6" 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_01a03a22-9415-7cf7-9bbd-444d008eef46" xlink:to="loc_country_US_01a03a22-9415-7ccf-82ed-8ea12ba5a4c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_01a03a22-9415-7e88-9981-1cccfba56123" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_01a03a22-9415-7cf7-9bbd-444d008eef46" xlink:to="loc_country_CA_01a03a22-9415-7e88-9981-1cccfba56123" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_OtherCountriesMember_01a03a22-9415-72d4-9032-d8615c048eb5" xlink:href="ait-20260930.xsd#ait_OtherCountriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_01a03a22-9415-7cf7-9bbd-444d008eef46" xlink:to="loc_ait_OtherCountriesMember_01a03a22-9415-72d4-9032-d8615c048eb5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_01a03a22-9415-76b1-956e-52fa3a172755" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_01a03a22-9415-76ed-a829-28f56d4864e3" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_01a03a22-9415-76b1-956e-52fa3a172755" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/REVENUERECOGNITIONScheduleofRevenuebyReportableSegmentandMajorCustomerIndustryDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#REVENUERECOGNITIONScheduleofRevenuebyReportableSegmentandMajorCustomerIndustryDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/REVENUERECOGNITIONScheduleofRevenuebyReportableSegmentandMajorCustomerIndustryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_01a03a22-9415-7e9c-9c04-467e2ce0b899" 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_01a03a22-9415-7c6a-a07a-8d55fb26d535" 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_01a03a22-9415-7e9c-9c04-467e2ce0b899" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_01a03a22-9415-7c6a-a07a-8d55fb26d535" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9415-720c-a8d5-8062e8574899" 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_01a03a22-9415-7c6a-a07a-8d55fb26d535" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9415-720c-a8d5-8062e8574899" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9415-720c-a8d5-8062e8574899_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_01a03a22-9415-720c-a8d5-8062e8574899" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9415-720c-a8d5-8062e8574899_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9415-735c-a055-f56c738d9067" 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_01a03a22-9415-720c-a8d5-8062e8574899" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9415-735c-a055-f56c738d9067" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9415-7fe8-98cd-1017ee73fe40" xlink:href="ait-20260930.xsd#ait_ServiceCenterBasedDistributionSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9415-735c-a055-f56c738d9067" xlink:to="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9415-7fe8-98cd-1017ee73fe40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9415-762d-89df-d0e33118889c" xlink:href="ait-20260930.xsd#ait_EngineeredSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9415-735c-a055-f56c738d9067" xlink:to="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9415-762d-89df-d0e33118889c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesByIndustryAxis_01a03a22-9415-79a8-80a4-ddb76849d41a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_01a03a22-9415-7c6a-a07a-8d55fb26d535" xlink:to="loc_us-gaap_EquitySecuritiesByIndustryAxis_01a03a22-9415-79a8-80a4-ddb76849d41a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_01a03a22-9415-79a8-80a4-ddb76849d41a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_01a03a22-9415-79a8-80a4-ddb76849d41a" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_01a03a22-9415-79a8-80a4-ddb76849d41a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_01a03a22-9415-7e89-a63c-113f89d1fb8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_01a03a22-9415-79a8-80a4-ddb76849d41a" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_01a03a22-9415-7e89-a63c-113f89d1fb8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialAndIndustrialSectorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_01a03a22-9415-7e89-a63c-113f89d1fb8b" xlink:to="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_GeneralIndustryMember_01a03a22-9415-73f6-9788-ad3b4938a392" xlink:href="ait-20260930.xsd#ait_GeneralIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_GeneralIndustryMember_01a03a22-9415-73f6-9788-ad3b4938a392" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_IndustrialMachineryMember_01a03a22-9415-74de-bb5c-495afdb74611" xlink:href="ait-20260930.xsd#ait_IndustrialMachineryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_IndustrialMachineryMember_01a03a22-9415-74de-bb5c-495afdb74611" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_MetalsMember_01a03a22-9415-7c73-9aba-4041f8b4dbf2" xlink:href="ait-20260930.xsd#ait_MetalsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_MetalsMember_01a03a22-9415-7c73-9aba-4041f8b4dbf2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_FoodMember_01a03a22-9415-75c3-8805-2a125fb0db33" xlink:href="ait-20260930.xsd#ait_FoodMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_FoodMember_01a03a22-9415-75c3-8805-2a125fb0db33" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ForestProductsMember_01a03a22-9415-7481-8647-66f73aa96f80" xlink:href="ait-20260930.xsd#ait_ForestProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_ForestProductsMember_01a03a22-9415-7481-8647-66f73aa96f80" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ChemPetrochemMember_01a03a22-9415-70bf-a657-de502917c57d" xlink:href="ait-20260930.xsd#ait_ChemPetrochemMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_ChemPetrochemMember_01a03a22-9415-70bf-a657-de502917c57d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_CementAggregateMember_01a03a22-9415-7195-ba32-09c4c381df52" xlink:href="ait-20260930.xsd#ait_CementAggregateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_CementAggregateMember_01a03a22-9415-7195-ba32-09c4c381df52" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_OilGasMember_01a03a22-9415-7a8f-9a91-320c8dce3467" xlink:href="ait-20260930.xsd#ait_OilGasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_OilGasMember_01a03a22-9415-7a8f-9a91-320c8dce3467" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_TransportationMember_01a03a22-9415-75cf-8be4-46af0843fc60" xlink:href="ait-20260930.xsd#ait_TransportationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommercialAndIndustrialSectorMember_01a03a22-9415-776c-a369-0474d703fd62" xlink:to="loc_ait_TransportationMember_01a03a22-9415-75cf-8be4-46af0843fc60" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_DisaggregatedRevenueByCustomerIndustryPercent_01a03a22-9415-712a-b939-8e92cd16cab3" xlink:href="ait-20260930.xsd#ait_DisaggregatedRevenueByCustomerIndustryPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_01a03a22-9415-7e9c-9c04-467e2ce0b899" xlink:to="loc_ait_DisaggregatedRevenueByCustomerIndustryPercent_01a03a22-9415-712a-b939-8e92cd16cab3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/REVENUERECOGNITIONScheduleofRevenuebyReportableSegmentandProductLineDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#REVENUERECOGNITIONScheduleofRevenuebyReportableSegmentandProductLineDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/REVENUERECOGNITIONScheduleofRevenuebyReportableSegmentandProductLineDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_01a03a22-9415-734c-8652-825067828c53" 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_01a03a22-9415-7643-9f15-a9c798b0d62d" 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_01a03a22-9415-734c-8652-825067828c53" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_01a03a22-9415-7643-9f15-a9c798b0d62d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9415-7b69-acab-4b6299dce7e9" 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_01a03a22-9415-7643-9f15-a9c798b0d62d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9415-7b69-acab-4b6299dce7e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9415-7b69-acab-4b6299dce7e9_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_01a03a22-9415-7b69-acab-4b6299dce7e9" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9415-7b69-acab-4b6299dce7e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9415-7324-b60b-42e33d1d5168" 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_01a03a22-9415-7b69-acab-4b6299dce7e9" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9415-7324-b60b-42e33d1d5168" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9415-75d9-b117-ea88812755a7" xlink:href="ait-20260930.xsd#ait_ServiceCenterBasedDistributionSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9415-7324-b60b-42e33d1d5168" xlink:to="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9415-75d9-b117-ea88812755a7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9415-78eb-98e6-3516cf2dc0ee" xlink:href="ait-20260930.xsd#ait_EngineeredSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9415-7324-b60b-42e33d1d5168" xlink:to="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9415-78eb-98e6-3516cf2dc0ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_01a03a22-9415-71c4-9976-8fa713a133fb" 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_01a03a22-9415-7643-9f15-a9c798b0d62d" xlink:to="loc_srt_ProductOrServiceAxis_01a03a22-9415-71c4-9976-8fa713a133fb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_01a03a22-9415-71c4-9976-8fa713a133fb_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_01a03a22-9415-71c4-9976-8fa713a133fb" xlink:to="loc_srt_ProductsAndServicesDomain_01a03a22-9415-71c4-9976-8fa713a133fb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_01a03a22-9415-76fa-85fa-6a87b4acd503" 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_01a03a22-9415-71c4-9976-8fa713a133fb" xlink:to="loc_srt_ProductsAndServicesDomain_01a03a22-9415-76fa-85fa-6a87b4acd503" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_PowerTransmissionMember_01a03a22-9415-78cd-8eee-df26eb8a6d59" xlink:href="ait-20260930.xsd#ait_PowerTransmissionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_01a03a22-9415-76fa-85fa-6a87b4acd503" xlink:to="loc_ait_PowerTransmissionMember_01a03a22-9415-78cd-8eee-df26eb8a6d59" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_GeneralMaintenanceHoseProductsOtherMember_01a03a22-9415-78cd-bc9d-a9f90ddb1d61" xlink:href="ait-20260930.xsd#ait_GeneralMaintenanceHoseProductsOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_01a03a22-9415-76fa-85fa-6a87b4acd503" xlink:to="loc_ait_GeneralMaintenanceHoseProductsOtherMember_01a03a22-9415-78cd-bc9d-a9f90ddb1d61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_FluidPowerMember_01a03a22-9415-79c1-b40c-42bfddde1d7f" xlink:href="ait-20260930.xsd#ait_FluidPowerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_01a03a22-9415-76fa-85fa-6a87b4acd503" xlink:to="loc_ait_FluidPowerMember_01a03a22-9415-79c1-b40c-42bfddde1d7f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_BearingsLinearSealsMember_01a03a22-9415-7623-a338-03831fc33bd4" xlink:href="ait-20260930.xsd#ait_BearingsLinearSealsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_01a03a22-9415-76fa-85fa-6a87b4acd503" xlink:to="loc_ait_BearingsLinearSealsMember_01a03a22-9415-7623-a338-03831fc33bd4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_SpecialtyFlowControlMember_01a03a22-9415-7b0f-9dc9-3e50c860e036" xlink:href="ait-20260930.xsd#ait_SpecialtyFlowControlMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_01a03a22-9415-76fa-85fa-6a87b4acd503" xlink:to="loc_ait_SpecialtyFlowControlMember_01a03a22-9415-7b0f-9dc9-3e50c860e036" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_DisaggregatedRevenueByProductLinePercent_01a03a22-9415-7be8-b742-6e2588989721" xlink:href="ait-20260930.xsd#ait_DisaggregatedRevenueByProductLinePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_01a03a22-9415-734c-8652-825067828c53" xlink:to="loc_ait_DisaggregatedRevenueByProductLinePercent_01a03a22-9415-7be8-b742-6e2588989721" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/BUSINESSCOMBINATIONSDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#BUSINESSCOMBINATIONSDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/BUSINESSCOMBINATIONSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_01a134ab-5cd3-753e-9d12-4306fe9422ac" 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_01a03a22-9415-7103-9461-a78225ad654a" 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_01a134ab-5cd3-753e-9d12-4306fe9422ac" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_01a03a22-9415-7103-9461-a78225ad654a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_01a134ab-5cd3-7d10-866c-7c00ad29a407" 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_01a03a22-9415-7103-9461-a78225ad654a" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_01a134ab-5cd3-7d10-866c-7c00ad29a407" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a134ab-5cd3-7d10-866c-7c00ad29a407_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_01a134ab-5cd3-7d10-866c-7c00ad29a407" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a134ab-5cd3-7d10-866c-7c00ad29a407_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a134ab-5cd3-73d0-b3e6-b9b50e089e6c" 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_01a134ab-5cd3-7d10-866c-7c00ad29a407" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a134ab-5cd3-73d0-b3e6-b9b50e089e6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ThompsonIndustrialSupplyMember_01a134ab-5cd3-7078-8236-15b5b3ffb6c1" xlink:href="ait-20260930.xsd#ait_ThompsonIndustrialSupplyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a134ab-5cd3-73d0-b3e6-b9b50e089e6c" xlink:to="loc_ait_ThompsonIndustrialSupplyMember_01a134ab-5cd3-7078-8236-15b5b3ffb6c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_01a134ab-5cd3-7bd1-8272-5dea36682e34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a134ab-5cd3-753e-9d12-4306fe9422ac" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_01a134ab-5cd3-7bd1-8272-5dea36682e34" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_BusinessCombinationRecognizedAssetsAcquiredNetTangibleAssets_01a134ab-5cd3-7f0d-9b26-3d7885925d32" xlink:href="ait-20260930.xsd#ait_BusinessCombinationRecognizedAssetsAcquiredNetTangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a134ab-5cd3-753e-9d12-4306fe9422ac" xlink:to="loc_ait_BusinessCombinationRecognizedAssetsAcquiredNetTangibleAssets_01a134ab-5cd3-7f0d-9b26-3d7885925d32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_01a134ab-5cd3-7c3d-bc45-ff977ab1cf75" 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_01a134ab-5cd3-753e-9d12-4306fe9422ac" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_01a134ab-5cd3-7c3d-bc45-ff977ab1cf75" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_01a134ab-5cd3-78d9-93e1-4a07a5863dfa" 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_01a134ab-5cd3-753e-9d12-4306fe9422ac" xlink:to="loc_us-gaap_Goodwill_01a134ab-5cd3-78d9-93e1-4a07a5863dfa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_01a134ab-5cd3-7c9d-8064-a58498c51e12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a134ab-5cd3-753e-9d12-4306fe9422ac" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_01a134ab-5cd3-7c9d-8064-a58498c51e12" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_BusinessCombinationContingentConsiderationInterestRate_01a134ab-5cd3-74f8-a490-49f230c9664e" xlink:href="ait-20260930.xsd#ait_BusinessCombinationContingentConsiderationInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_01a134ab-5cd3-753e-9d12-4306fe9422ac" xlink:to="loc_ait_BusinessCombinationContingentConsiderationInterestRate_01a134ab-5cd3-74f8-a490-49f230c9664e" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/GOODWILLANDINTANGIBLESScheduleofGoodwillDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#GOODWILLANDINTANGIBLESScheduleofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/GOODWILLANDINTANGIBLESScheduleofGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7b9a-bd4f-fe1fbb3969fe" 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_01a03a22-9416-75e5-8cc1-965b7d81268d" 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_01a03a22-9416-7b9a-bd4f-fe1fbb3969fe" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_01a03a22-9416-75e5-8cc1-965b7d81268d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9416-73fc-af52-51009dd036bf" 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_01a03a22-9416-75e5-8cc1-965b7d81268d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9416-73fc-af52-51009dd036bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9416-73fc-af52-51009dd036bf_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_01a03a22-9416-73fc-af52-51009dd036bf" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9416-73fc-af52-51009dd036bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9416-718e-9fb5-1035f24d0af8" 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_01a03a22-9416-73fc-af52-51009dd036bf" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9416-718e-9fb5-1035f24d0af8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9416-7484-919a-5c8714117440" xlink:href="ait-20260930.xsd#ait_ServiceCenterBasedDistributionSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9416-718e-9fb5-1035f24d0af8" xlink:to="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9416-7484-919a-5c8714117440" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9416-79e8-a0c6-2b51b582ff29" xlink:href="ait-20260930.xsd#ait_EngineeredSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9416-718e-9fb5-1035f24d0af8" xlink:to="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9416-79e8-a0c6-2b51b582ff29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_01a03a22-9416-7cc0-8fdb-ab496a6bbc81" 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_01a03a22-9416-7b9a-bd4f-fe1fbb3969fe" xlink:to="loc_us-gaap_GoodwillRollForward_01a03a22-9416-7cc0-8fdb-ab496a6bbc81" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_01a03a22-9416-75a0-892d-d57173d2689c" 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_01a03a22-9416-7cc0-8fdb-ab496a6bbc81" xlink:to="loc_us-gaap_Goodwill_01a03a22-9416-75a0-892d-d57173d2689c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_01a03a22-9416-77b2-af23-f43933d13df4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_01a03a22-9416-7cc0-8fdb-ab496a6bbc81" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_01a03a22-9416-77b2-af23-f43933d13df4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments_01a03a22-9416-7390-bddc-207b8a773640" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_01a03a22-9416-7cc0-8fdb-ab496a6bbc81" xlink:to="loc_us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments_01a03a22-9416-7390-bddc-207b8a773640" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_01a03a22-9416-752d-ad48-3d551d2415f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/GOODWILLANDINTANGIBLESNarrativeDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#GOODWILLANDINTANGIBLESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/GOODWILLANDINTANGIBLESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" 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_01a03a22-9416-7e3a-8900-6995976ad2ca" 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_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_01a03a22-9416-7e3a-8900-6995976ad2ca" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9416-7669-aa52-d3f83e1b58a0" 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_01a03a22-9416-7e3a-8900-6995976ad2ca" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-9416-7669-aa52-d3f83e1b58a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9416-7669-aa52-d3f83e1b58a0_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_01a03a22-9416-7669-aa52-d3f83e1b58a0" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9416-7669-aa52-d3f83e1b58a0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-9416-7b4e-8ead-8dc55a68048a" 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_01a03a22-9416-7669-aa52-d3f83e1b58a0" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-9416-7b4e-8ead-8dc55a68048a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9416-72fd-ab6d-3bfd98e9a7be" xlink:href="ait-20260930.xsd#ait_ServiceCenterBasedDistributionSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9416-7b4e-8ead-8dc55a68048a" xlink:to="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-9416-72fd-ab6d-3bfd98e9a7be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9416-7afc-837b-c3f94f8262cf" xlink:href="ait-20260930.xsd#ait_EngineeredSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-9416-7b4e-8ead-8dc55a68048a" xlink:to="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-9416-7afc-837b-c3f94f8262cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportingUnits_01a03a22-9416-7ae4-9194-44ca7675d9a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportingUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_NumberOfReportingUnits_01a03a22-9416-7ae4-9194-44ca7675d9a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_01a03a22-9416-79ff-a2a8-4aecaa0f3f3c" 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_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_GoodwillImpairedAccumulatedImpairmentLoss_01a03a22-9416-79ff-a2a8-4aecaa0f3f3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_01a03a22-9416-7155-bed2-ba87a1b3a27e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_01a03a22-9416-7155-bed2-ba87a1b3a27e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_01a03a22-9416-7282-a860-e7f73e7c5f2f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_01a03a22-9416-7282-a860-e7f73e7c5f2f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_01a03a22-9416-74df-8b4c-48e71f5cb488" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_01a03a22-9416-74df-8b4c-48e71f5cb488" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_01a03a22-9416-743d-b598-ecd899c9ca50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_01a03a22-9416-743d-b598-ecd899c9ca50" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_01a03a22-9416-78dd-a56e-b758b74f5b34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_01a03a22-9416-78dd-a56e-b758b74f5b34" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_01a03a22-9416-76a7-9c4a-6e0589971739" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a03a22-9416-7250-acf8-e8f66d486b74" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_01a03a22-9416-76a7-9c4a-6e0589971739" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/GOODWILLANDINTANGIBLESScheduleofIntangibleAssetsDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#GOODWILLANDINTANGIBLESScheduleofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/GOODWILLANDINTANGIBLESScheduleofIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a03a22-9416-7861-8a0b-6225cb42ddf2" 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_01a03a22-9416-7b1d-ae42-5eaf733b5716" 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_01a03a22-9416-7861-8a0b-6225cb42ddf2" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_01a03a22-9416-7b1d-ae42-5eaf733b5716" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a03a22-9416-7310-b022-d636f833d184" 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_01a03a22-9416-7b1d-ae42-5eaf733b5716" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a03a22-9416-7310-b022-d636f833d184" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a03a22-9416-7310-b022-d636f833d184_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_01a03a22-9416-7310-b022-d636f833d184" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a03a22-9416-7310-b022-d636f833d184_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a03a22-9416-787a-8764-1a068b671d86" 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_01a03a22-9416-7310-b022-d636f833d184" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a03a22-9416-787a-8764-1a068b671d86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_01a03a22-9416-7e3a-acf5-a817ce849414" 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_01a03a22-9416-787a-8764-1a068b671d86" xlink:to="loc_us-gaap_CustomerRelationshipsMember_01a03a22-9416-7e3a-acf5-a817ce849414" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_01a03a22-9416-7439-93d1-8042bc9ab1eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a03a22-9416-787a-8764-1a068b671d86" xlink:to="loc_us-gaap_TradeNamesMember_01a03a22-9416-7439-93d1-8042bc9ab1eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_01a03a22-9416-78dd-9adf-747927a66a23" 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_01a03a22-9416-787a-8764-1a068b671d86" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_01a03a22-9416-78dd-9adf-747927a66a23" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_01a03a22-9416-78eb-b752-6d5bf4031107" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_01a03a22-9416-7861-8a0b-6225cb42ddf2" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_01a03a22-9416-78eb-b752-6d5bf4031107" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a03a22-9416-716d-a406-11664d33454e" 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_IntangibleAssetsNetExcludingGoodwillAbstract_01a03a22-9416-78eb-b752-6d5bf4031107" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a03a22-9416-716d-a406-11664d33454e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a03a22-9416-771d-bb27-9cf0087e3f59" 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_IntangibleAssetsNetExcludingGoodwillAbstract_01a03a22-9416-78eb-b752-6d5bf4031107" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a03a22-9416-771d-bb27-9cf0087e3f59" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a03a22-9416-7afc-a53f-da83634805aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_01a03a22-9416-78eb-b752-6d5bf4031107" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a03a22-9416-7afc-a53f-da83634805aa" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/DEBTScheduleofDebtDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#DEBTScheduleofDebtDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/DEBTScheduleofDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_01a03a22-9416-74e1-bcee-5849f44a7585" 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_01a03a22-9416-745c-84bb-67fd0f7ddd43" 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_01a03a22-9416-74e1-bcee-5849f44a7585" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_01a03a22-9416-745c-84bb-67fd0f7ddd43" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a03a22-9416-749a-ad0b-570ffda56c48" 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_01a03a22-9416-745c-84bb-67fd0f7ddd43" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a03a22-9416-749a-ad0b-570ffda56c48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-749a-ad0b-570ffda56c48_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_01a03a22-9416-749a-ad0b-570ffda56c48" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-749a-ad0b-570ffda56c48_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-7621-8006-d2d34734fda6" 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_01a03a22-9416-749a-ad0b-570ffda56c48" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-7621-8006-d2d34734fda6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember_01a03a22-9416-7f26-99a0-a68f2de4a673" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-7621-8006-d2d34734fda6" xlink:to="loc_us-gaap_AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember_01a03a22-9416-7f26-99a0-a68f2de4a673" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_01a03a22-9416-7a1c-b033-0880aced3333" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a03a22-9416-74e1-bcee-5849f44a7585" xlink:to="loc_us-gaap_LineOfCredit_01a03a22-9416-7a1c-b033-0880aced3333" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrincipalAmountOutstandingOnLoansSecuritized_01a03a22-9416-7912-b24a-9b59ff709c92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PrincipalAmountOutstandingOnLoansSecuritized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a03a22-9416-74e1-bcee-5849f44a7585" xlink:to="loc_us-gaap_PrincipalAmountOutstandingOnLoansSecuritized_01a03a22-9416-7912-b24a-9b59ff709c92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_01a03a22-9416-73e0-a757-c7e28d490e77" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_01a03a22-9416-74e1-bcee-5849f44a7585" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_01a03a22-9416-73e0-a757-c7e28d490e77" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/DEBTNarrativeDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#DEBTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/DEBTNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_01a03a22-9416-758f-bc96-302051ca2473" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_DebtInstrumentTable_01a03a22-9416-758f-bc96-302051ca2473" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_01a03a22-9416-79a4-b9c7-944b68f02dcb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a03a22-9416-758f-bc96-302051ca2473" xlink:to="loc_us-gaap_CreditFacilityAxis_01a03a22-9416-79a4-b9c7-944b68f02dcb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a03a22-9416-79a4-b9c7-944b68f02dcb_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_01a03a22-9416-79a4-b9c7-944b68f02dcb" xlink:to="loc_us-gaap_CreditFacilityDomain_01a03a22-9416-79a4-b9c7-944b68f02dcb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a03a22-9416-713b-81a0-421e5ebc29c6" 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_01a03a22-9416-79a4-b9c7-944b68f02dcb" xlink:to="loc_us-gaap_CreditFacilityDomain_01a03a22-9416-713b-81a0-421e5ebc29c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_01a03a22-9416-75a7-b2c3-c8758098e064" 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_01a03a22-9416-713b-81a0-421e5ebc29c6" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_01a03a22-9416-75a7-b2c3-c8758098e064" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_01a03a22-9416-741d-b2bd-a2c0114cdd07" 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_DebtInstrumentTable_01a03a22-9416-758f-bc96-302051ca2473" xlink:to="loc_srt_RangeAxis_01a03a22-9416-741d-b2bd-a2c0114cdd07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a03a22-9416-741d-b2bd-a2c0114cdd07_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_01a03a22-9416-741d-b2bd-a2c0114cdd07" xlink:to="loc_srt_RangeMember_01a03a22-9416-741d-b2bd-a2c0114cdd07_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a03a22-9416-7171-acc0-6c5826adbbd7" 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_01a03a22-9416-741d-b2bd-a2c0114cdd07" xlink:to="loc_srt_RangeMember_01a03a22-9416-7171-acc0-6c5826adbbd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_01a03a22-9416-72e6-8151-51a9a43b9df7" 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_01a03a22-9416-7171-acc0-6c5826adbbd7" xlink:to="loc_srt_MinimumMember_01a03a22-9416-72e6-8151-51a9a43b9df7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_01a03a22-9416-7573-9c18-e1b433120ce9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a03a22-9416-7171-acc0-6c5826adbbd7" xlink:to="loc_srt_MaximumMember_01a03a22-9416-7573-9c18-e1b433120ce9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a03a22-9416-7119-a97f-0795fce8f316" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a03a22-9416-758f-bc96-302051ca2473" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a03a22-9416-7119-a97f-0795fce8f316" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a03a22-9416-7119-a97f-0795fce8f316_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_01a03a22-9416-7119-a97f-0795fce8f316" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a03a22-9416-7119-a97f-0795fce8f316_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a03a22-9416-723e-a4dc-a52334fcc7e3" 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_01a03a22-9416-7119-a97f-0795fce8f316" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a03a22-9416-723e-a4dc-a52334fcc7e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_SwingLineLoansMember_01a03a22-9416-7406-b61e-1449d05a9b01" xlink:href="ait-20260930.xsd#ait_SwingLineLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a03a22-9416-723e-a4dc-a52334fcc7e3" xlink:to="loc_ait_SwingLineLoansMember_01a03a22-9416-7406-b61e-1449d05a9b01" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_01a03a22-9416-7ee8-971a-8924db51b12c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a03a22-9416-723e-a4dc-a52334fcc7e3" xlink:to="loc_us-gaap_LetterOfCreditMember_01a03a22-9416-7ee8-971a-8924db51b12c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a03a22-9416-71df-af83-3b400d6b27e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a03a22-9416-758f-bc96-302051ca2473" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a03a22-9416-71df-af83-3b400d6b27e0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-71df-af83-3b400d6b27e0_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_01a03a22-9416-71df-af83-3b400d6b27e0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-71df-af83-3b400d6b27e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-7632-9049-d2bae87e9cb6" 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_01a03a22-9416-71df-af83-3b400d6b27e0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-7632-9049-d2bae87e9cb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember_01a03a22-9416-7999-8221-dcc2319a9538" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a03a22-9416-7632-9049-d2bae87e9cb6" xlink:to="loc_us-gaap_AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember_01a03a22-9416-7999-8221-dcc2319a9538" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_01a03a22-9416-78bc-90b5-e22fca4d22d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_DebtInstrumentTerm_01a03a22-9416-78bc-90b5-e22fca4d22d1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a03a22-9416-777f-b490-3f9be1621738" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a03a22-9416-777f-b490-3f9be1621738" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_01a03a22-9416-7764-aad5-d33595f3189e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_01a03a22-9416-7764-aad5-d33595f3189e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_VariableInterestRateBaseRatePlusMargin_01a03a22-9416-76e6-bbe9-c60d1e91af94" xlink:href="ait-20260930.xsd#ait_VariableInterestRateBaseRatePlusMargin"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_ait_VariableInterestRateBaseRatePlusMargin_01a03a22-9416-76e6-bbe9-c60d1e91af94" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_VariableInterestRateSOFRPlusMargin_01a03a22-9416-7700-b336-5c5e8212647e" xlink:href="ait-20260930.xsd#ait_VariableInterestRateSOFRPlusMargin"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_ait_VariableInterestRateSOFRPlusMargin_01a03a22-9416-7700-b336-5c5e8212647e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_01a03a22-9416-7d8e-80e0-3c3a8f2f557b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_01a03a22-9416-7d8e-80e0-3c3a8f2f557b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_01a03a22-9416-7e2c-ad1f-9cb933fe1b27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_01a03a22-9416-7e2c-ad1f-9cb933fe1b27" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtPercentageBearingVariableInterestRate_01a03a22-9416-7bd9-9543-2e605e8fcc75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtPercentageBearingVariableInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_LongTermDebtPercentageBearingVariableInterestRate_01a03a22-9416-7bd9-9543-2e605e8fcc75" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_01a080e0-19b9-7284-bc06-3f64d29e5a0a" 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_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_01a080e0-19b9-7284-bc06-3f64d29e5a0a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a03a22-9416-78ea-8f96-6b594969691e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a03a22-9416-7c50-b61c-a667a44175f8" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a03a22-9416-78ea-8f96-6b594969691e" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/FAIRVALUEMEASUREMENTSDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#FAIRVALUEMEASUREMENTSDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/FAIRVALUEMEASUREMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a03a22-9416-7692-b010-d426b9ae8e3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a03a22-9416-7e82-b789-f4d7d655ef24" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a03a22-9416-7692-b010-d426b9ae8e3e" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a03a22-9416-7e82-b789-f4d7d655ef24" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a03a22-9416-7162-973f-8182d7fb4e55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a03a22-9416-7e82-b789-f4d7d655ef24" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a03a22-9416-7162-973f-8182d7fb4e55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a03a22-9416-7162-973f-8182d7fb4e55_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a03a22-9416-7162-973f-8182d7fb4e55" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a03a22-9416-7162-973f-8182d7fb4e55_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a03a22-9416-7436-87b2-3d8d1f4a7111" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a03a22-9416-7162-973f-8182d7fb4e55" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a03a22-9416-7436-87b2-3d8d1f4a7111" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_01a03a22-9416-799a-a101-e2d048906994" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a03a22-9416-7436-87b2-3d8d1f4a7111" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_01a03a22-9416-799a-a101-e2d048906994" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_01a03a22-9416-7607-aff9-01dbf0bdb3a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a03a22-9416-7436-87b2-3d8d1f4a7111" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_01a03a22-9416-7607-aff9-01dbf0bdb3a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a03a22-9416-7be5-9b99-7fd6aa06db61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a03a22-9416-7e82-b789-f4d7d655ef24" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a03a22-9416-7be5-9b99-7fd6aa06db61" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a03a22-9416-7be5-9b99-7fd6aa06db61_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a03a22-9416-7be5-9b99-7fd6aa06db61" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a03a22-9416-7be5-9b99-7fd6aa06db61_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a03a22-9416-7a6f-9b97-30138390dc45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a03a22-9416-7be5-9b99-7fd6aa06db61" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a03a22-9416-7a6f-9b97-30138390dc45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_01a03a22-9416-7034-ba0e-745a566ddf6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a03a22-9416-7a6f-9b97-30138390dc45" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_01a03a22-9416-7034-ba0e-745a566ddf6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure_01a03a22-9416-7831-8101-ea1693739af4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a03a22-9416-7692-b010-d426b9ae8e3e" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosure_01a03a22-9416-7831-8101-ea1693739af4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashSurrenderValueFairValueDisclosure_01a03a22-9416-7130-b7a0-924c9689caad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashSurrenderValueFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a03a22-9416-7692-b010-d426b9ae8e3e" xlink:to="loc_us-gaap_CashSurrenderValueFairValueDisclosure_01a03a22-9416-7130-b7a0-924c9689caad" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/SHAREHOLDERSEQUITYScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#SHAREHOLDERSEQUITYScheduleofAccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/SHAREHOLDERSEQUITYScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_01a03a22-94cd-788d-8a67-8adceb1f86a2" 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_01a03a22-9416-7020-bb05-d15a1760dd6d" 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_01a03a22-94cd-788d-8a67-8adceb1f86a2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_01a03a22-9416-7020-bb05-d15a1760dd6d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_01a03a22-9416-7a9f-9017-16be08c1841c" 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_01a03a22-9416-7020-bb05-d15a1760dd6d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_01a03a22-9416-7a9f-9017-16be08c1841c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a03a22-9416-7a9f-9017-16be08c1841c_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_01a03a22-9416-7a9f-9017-16be08c1841c" xlink:to="loc_us-gaap_EquityComponentDomain_01a03a22-9416-7a9f-9017-16be08c1841c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a03a22-9416-730e-a4be-a68112358bf3" 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_01a03a22-9416-7a9f-9017-16be08c1841c" xlink:to="loc_us-gaap_EquityComponentDomain_01a03a22-9416-730e-a4be-a68112358bf3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_01a03a22-9416-774b-adc1-d82d57349e95" 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_EquityComponentDomain_01a03a22-9416-730e-a4be-a68112358bf3" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_01a03a22-9416-774b-adc1-d82d57349e95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_01a03a22-94cd-74a6-a9dd-549c317eae61" 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_EquityComponentDomain_01a03a22-9416-730e-a4be-a68112358bf3" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_01a03a22-94cd-74a6-a9dd-549c317eae61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_01a03a22-94cd-7e54-bf16-65cf2ed68e03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a03a22-9416-730e-a4be-a68112358bf3" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_01a03a22-94cd-7e54-bf16-65cf2ed68e03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a03a22-94cd-7488-b020-78d73ae92267" 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_01a03a22-9416-730e-a4be-a68112358bf3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a03a22-94cd-7488-b020-78d73ae92267" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_01a03a22-94cd-7cc9-8baf-118a785aab31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_01a03a22-9416-7020-bb05-d15a1760dd6d" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_01a03a22-94cd-7cc9-8baf-118a785aab31" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_01a03a22-94cd-7cc9-8baf-118a785aab31_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_01a03a22-94cd-7cc9-8baf-118a785aab31" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_01a03a22-94cd-7cc9-8baf-118a785aab31_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_01a03a22-94cd-7d72-8771-829852515061" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_01a03a22-94cd-7cc9-8baf-118a785aab31" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_01a03a22-94cd-7d72-8771-829852515061" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_01a03a22-94cd-7aa5-98c1-5fcb8ab8ab0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_01a03a22-94cd-7d72-8771-829852515061" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_01a03a22-94cd-7aa5-98c1-5fcb8ab8ab0d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationRollForward_01a03a22-94cd-73d4-b3dc-5626c7108840" xlink:href="ait-20260930.xsd#ait_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_01a03a22-94cd-788d-8a67-8adceb1f86a2" xlink:to="loc_ait_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationRollForward_01a03a22-94cd-73d4-b3dc-5626c7108840" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax_01a03a22-94cd-717e-b35b-afbf6d4241e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationRollForward_01a03a22-94cd-73d4-b3dc-5626c7108840" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax_01a03a22-94cd-717e-b35b-afbf6d4241e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax_01a03a22-94cd-7983-ad3b-21c337dc588a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationRollForward_01a03a22-94cd-73d4-b3dc-5626c7108840" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax_01a03a22-94cd-7983-ad3b-21c337dc588a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_01a03a22-94cd-79a9-aaec-9467dd2dc2ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationRollForward_01a03a22-94cd-73d4-b3dc-5626c7108840" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_01a03a22-94cd-79a9-aaec-9467dd2dc2ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_01a03a22-94cd-7451-a889-303200c4b6f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationRollForward_01a03a22-94cd-73d4-b3dc-5626c7108840" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_01a03a22-94cd-7451-a889-303200c4b6f9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax_01a03a22-94cd-7d7a-bae4-7a6970407900" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanRollForward_01a03a22-94cd-7d79-8c61-1abf8656243b" xlink:href="ait-20260930.xsd#ait_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_01a03a22-94cd-788d-8a67-8adceb1f86a2" xlink:to="loc_ait_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanRollForward_01a03a22-94cd-7d79-8c61-1abf8656243b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_01a03a22-94cd-753f-9e8b-a9c09cf444b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanRollForward_01a03a22-94cd-7d79-8c61-1abf8656243b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_01a03a22-94cd-753f-9e8b-a9c09cf444b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax_01a03a22-94cd-7353-8250-cede6c5a77eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanRollForward_01a03a22-94cd-7d79-8c61-1abf8656243b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeReclassificationAdjustmentsNetOfTax_01a03a22-94cd-7353-8250-cede6c5a77eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_01a03a22-94cd-7bb4-aa3d-43c341cc63a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanRollForward_01a03a22-94cd-7d79-8c61-1abf8656243b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_01a03a22-94cd-7bb4-aa3d-43c341cc63a7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_01a03a22-94cd-713c-8c85-6648f347108b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPlanRollForward_01a03a22-94cd-7d79-8c61-1abf8656243b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_01a03a22-94cd-713c-8c85-6648f347108b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_01a03a22-94cd-7e23-a758-68309062cf7b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_AOCICashFlowHedgeCumulativeGainLossRollForward_01a03a22-94cd-71dd-b7a9-c9ecdfc72734" xlink:href="ait-20260930.xsd#ait_AOCICashFlowHedgeCumulativeGainLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_01a03a22-94cd-788d-8a67-8adceb1f86a2" xlink:to="loc_ait_AOCICashFlowHedgeCumulativeGainLossRollForward_01a03a22-94cd-71dd-b7a9-c9ecdfc72734" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociLossCashFlowHedgeCumulativeGainLossAfterTax_01a03a22-94cd-787f-9e80-43b8a83162c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AociLossCashFlowHedgeCumulativeGainLossAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AOCICashFlowHedgeCumulativeGainLossRollForward_01a03a22-94cd-71dd-b7a9-c9ecdfc72734" xlink:to="loc_us-gaap_AociLossCashFlowHedgeCumulativeGainLossAfterTax_01a03a22-94cd-787f-9e80-43b8a83162c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_01a03a22-94cd-75ad-b6ee-7f0892b692fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AOCICashFlowHedgeCumulativeGainLossRollForward_01a03a22-94cd-71dd-b7a9-c9ecdfc72734" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_01a03a22-94cd-75ad-b6ee-7f0892b692fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_01a03a22-94cd-7d0a-889d-2e427768516f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AOCICashFlowHedgeCumulativeGainLossRollForward_01a03a22-94cd-71dd-b7a9-c9ecdfc72734" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_01a03a22-94cd-7d0a-889d-2e427768516f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_01a03a22-94cd-76b3-b019-73cf3bcb7b08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ait_AOCICashFlowHedgeCumulativeGainLossRollForward_01a03a22-94cd-71dd-b7a9-c9ecdfc72734" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_01a03a22-94cd-76b3-b019-73cf3bcb7b08" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociLossCashFlowHedgeCumulativeGainLossAfterTax_01a03a22-94cd-707c-b7e0-47d7f832da87" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AociLossCashFlowHedgeCumulativeGainLossAfterTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_01a03a22-94cd-7196-a179-c42f061ac5ab" 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_01a03a22-94cd-788d-8a67-8adceb1f86a2" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_01a03a22-94cd-7196-a179-c42f061ac5ab" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_01a03a22-94cd-7dbd-9f24-75da8efe914c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_01a03a22-94cd-7196-a179-c42f061ac5ab" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_01a03a22-94cd-7dbd-9f24-75da8efe914c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_01a03a22-94cd-770e-9e54-ce149ea2381b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_01a03a22-94cd-7196-a179-c42f061ac5ab" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_01a03a22-94cd-770e-9e54-ce149ea2381b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_01a03a22-94cd-7129-b1d1-c20c579f506a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a03a22-94cd-7159-a214-3c5ba55dfada" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_01a03a22-94cd-7196-a179-c42f061ac5ab" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a03a22-94cd-7159-a214-3c5ba55dfada" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_01a03a22-94cd-7e24-91bb-3d5f3e1e700e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/SEGMENTINFORMATIONScheduleofCorporateandOtherExpensesReconcileSegmentOperatingIncometoTotalConsolidatedIncomeDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#SEGMENTINFORMATIONScheduleofCorporateandOtherExpensesReconcileSegmentOperatingIncometoTotalConsolidatedIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/SEGMENTINFORMATIONScheduleofCorporateandOtherExpensesReconcileSegmentOperatingIncometoTotalConsolidatedIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_01a03a22-94cd-7e79-bbca-9117a9bdf573" 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_01a03a22-94cd-7806-b329-4a3b726823e1" 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_01a03a22-94cd-7e79-bbca-9117a9bdf573" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_01a03a22-94cd-7806-b329-4a3b726823e1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-94cd-725b-b47d-ae87b7127263" 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_01a03a22-94cd-7806-b329-4a3b726823e1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-94cd-725b-b47d-ae87b7127263" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-94cd-725b-b47d-ae87b7127263_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_01a03a22-94cd-725b-b47d-ae87b7127263" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-94cd-725b-b47d-ae87b7127263_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-94cd-7125-8746-db9f0d3efc34" 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_01a03a22-94cd-725b-b47d-ae87b7127263" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-94cd-7125-8746-db9f0d3efc34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-94cd-7ecc-b282-44f7c0616274" xlink:href="ait-20260930.xsd#ait_ServiceCenterBasedDistributionSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-94cd-7125-8746-db9f0d3efc34" xlink:to="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-94cd-7ecc-b282-44f7c0616274" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-94cd-7d2b-9c00-35838595b985" xlink:href="ait-20260930.xsd#ait_EngineeredSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-94cd-7125-8746-db9f0d3efc34" xlink:to="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-94cd-7d2b-9c00-35838595b985" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ReportableSegmentsMember_01a03a22-94cd-725e-a8ce-5880444ff089" xlink:href="ait-20260930.xsd#ait_ReportableSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-94cd-7125-8746-db9f0d3efc34" xlink:to="loc_ait_ReportableSegmentsMember_01a03a22-94cd-725e-a8ce-5880444ff089" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_01a03a22-94cd-7fa0-8af6-fbb694f3767b" 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_01a03a22-94cd-7806-b329-4a3b726823e1" xlink:to="loc_srt_ConsolidationItemsAxis_01a03a22-94cd-7fa0-8af6-fbb694f3767b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_01a03a22-94cd-7fa0-8af6-fbb694f3767b_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_01a03a22-94cd-7fa0-8af6-fbb694f3767b" xlink:to="loc_srt_ConsolidationItemsDomain_01a03a22-94cd-7fa0-8af6-fbb694f3767b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_01a03a22-94cd-7b3a-b5aa-634f49926889" 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_01a03a22-94cd-7fa0-8af6-fbb694f3767b" xlink:to="loc_srt_ConsolidationItemsDomain_01a03a22-94cd-7b3a-b5aa-634f49926889" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_01a03a22-94cd-7d84-bd82-3730aac43a81" 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_01a03a22-94cd-7b3a-b5aa-634f49926889" xlink:to="loc_us-gaap_OperatingSegmentsMember_01a03a22-94cd-7d84-bd82-3730aac43a81" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_01a03a22-94cd-7a41-9084-b50f999e5a67" 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_01a03a22-94cd-7b3a-b5aa-634f49926889" xlink:to="loc_us-gaap_IntersegmentEliminationMember_01a03a22-94cd-7a41-9084-b50f999e5a67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a03a22-94cd-7e79-bbca-9117a9bdf573" xlink:to="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_01a03a22-94cd-7a7f-a850-787bef8592b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_01a03a22-94cd-7a7f-a850-787bef8592b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_01a03a22-94cd-77b9-b12b-c41250894f3c" 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_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_01a03a22-94cd-77b9-b12b-c41250894f3c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_01a03a22-94cd-70e6-ab48-b250da3ffaef" 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_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_01a03a22-94cd-70e6-ab48-b250da3ffaef" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_01a03a22-94cd-7940-95de-7faf7c8671fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_us-gaap_OperatingIncomeLoss_01a03a22-94cd-7940-95de-7faf7c8671fb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_CorporateAndOtherExpenseNet_01a03a22-94cd-76b3-b50d-67cac5bee244" xlink:href="ait-20260930.xsd#ait_CorporateAndOtherExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_ait_CorporateAndOtherExpenseNet_01a03a22-94cd-76b3-b50d-67cac5bee244" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_01a03a22-94cd-7332-abf4-7fe0988c7387" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_01a03a22-94cd-7332-abf4-7fe0988c7387" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_01a03a22-94cd-7771-a97d-66af7f2f5b33" 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_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_01a03a22-94cd-7771-a97d-66af7f2f5b33" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a03a22-94cd-7b69-b61f-a186e00d56f1" 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_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract_01a03a22-94cd-7fce-80e5-257c0c1f3bbf" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_01a03a22-94cd-7b69-b61f-a186e00d56f1" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.applied.com/role/SEGMENTINFORMATIONScheduleofSegmentfinancialinformationDetails" xlink:type="simple" xlink:href="ait-20260930.xsd#SEGMENTINFORMATIONScheduleofSegmentfinancialinformationDetails"/>
  <link:definitionLink xlink:role="http://www.applied.com/role/SEGMENTINFORMATIONScheduleofSegmentfinancialinformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_01a03a22-94cd-76cb-8e6d-448c5a5e3e59" 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_01a03a22-94cd-7f1e-837e-f289f5ee9d05" 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_01a03a22-94cd-76cb-8e6d-448c5a5e3e59" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_01a03a22-94cd-7f1e-837e-f289f5ee9d05" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-94cd-7cbf-a4f8-a938a4d5bc2d" 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_01a03a22-94cd-7f1e-837e-f289f5ee9d05" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a03a22-94cd-7cbf-a4f8-a938a4d5bc2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-94cd-7cbf-a4f8-a938a4d5bc2d_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_01a03a22-94cd-7cbf-a4f8-a938a4d5bc2d" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-94cd-7cbf-a4f8-a938a4d5bc2d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a03a22-94cd-7871-b8fb-62b9d390fdb6" 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_01a03a22-94cd-7cbf-a4f8-a938a4d5bc2d" xlink:to="loc_us-gaap_SegmentDomain_01a03a22-94cd-7871-b8fb-62b9d390fdb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-94cd-7924-bee2-8a227bf38c26" xlink:href="ait-20260930.xsd#ait_ServiceCenterBasedDistributionSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-94cd-7871-b8fb-62b9d390fdb6" xlink:to="loc_ait_ServiceCenterBasedDistributionSegmentMember_01a03a22-94cd-7924-bee2-8a227bf38c26" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-94cd-7eaa-bce5-00c693e67132" xlink:href="ait-20260930.xsd#ait_EngineeredSolutionsSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a03a22-94cd-7871-b8fb-62b9d390fdb6" xlink:to="loc_ait_EngineeredSolutionsSegmentMember_01a03a22-94cd-7eaa-bce5-00c693e67132" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_01a03a22-94cd-7986-8bc9-a55dfced6947" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a03a22-94cd-76cb-8e6d-448c5a5e3e59" xlink:to="loc_us-gaap_Assets_01a03a22-94cd-7986-8bc9-a55dfced6947" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_01a03a22-94cd-7393-9d59-2ad4722e37dc" 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_SegmentReportingInformationLineItems_01a03a22-94cd-76cb-8e6d-448c5a5e3e59" xlink:to="loc_us-gaap_Depreciation_01a03a22-94cd-7393-9d59-2ad4722e37dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_01a03a22-94cd-76ec-abd8-f4e90371fb10" 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_01a03a22-94cd-76cb-8e6d-448c5a5e3e59" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_01a03a22-94cd-76ec-abd8-f4e90371fb10" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_01a03a22-94cd-7af7-9757-3ebaa1921d81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentExpenditureAdditionToLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a03a22-94cd-76cb-8e6d-448c5a5e3e59" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_01a03a22-94cd-7af7-9757-3ebaa1921d81" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_ait_DavidK.WellsMember_01a14159-9037-7ef0-86e7-73d59cf393e5" xlink:href="ait-20260930.xsd#ait_DavidK.WellsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_ait_DavidK.WellsMember_01a14159-9037-7ef0-86e7-73d59cf393e5" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
