<?xml version="1.0" encoding="us-ascii"?>
<!-- XBRL document created with Praxa -->
<!-- Copyright (c) 2026 Praxa LLC. All Rights Reserved.-->
<!-- Creation Date: 2026-09-14T10:33:17.3861+00:00 -->
<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:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" xlink:type="simple" />
  <link:roleRef roleURI="http://silynxcom.com/20260630/role/GeneralDetails" xlink:href="synx-20260630.xsd#GeneralDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://silynxcom.com/20260630/role/RevenueScheduleofRevenueDetails" xlink:href="synx-20260630.xsd#RevenueScheduleofRevenueDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://silynxcom.com/20260630/role/SubsequentEventsDetails" xlink:href="synx-20260630.xsd#SubsequentEventsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://silynxcom.com/20260630/role/UnauditedInterimCondensedConsolidatedStatementsofChangesinShareholdersEquity" xlink:href="synx-20260630.xsd#UnauditedInterimCondensedConsolidatedStatementsofChangesinShareholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://silynxcom.com/20260630/role/RelatedPartiesScheduleofTransactionswithRelatedPartiesDetails" xlink:href="synx-20260630.xsd#RelatedPartiesScheduleofTransactionswithRelatedPartiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://silynxcom.com/20260630/role/ShareBasedPaymentDetails" xlink:href="synx-20260630.xsd#ShareBasedPaymentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://silynxcom.com/20260630/role/ShareBasedPaymentScheduleofFairValueoftheOptionsDetails" xlink:href="synx-20260630.xsd#ShareBasedPaymentScheduleofFairValueoftheOptionsDetails" xlink:type="simple" />
  <link:definitionLink xlink:role="http://silynxcom.com/20260630/role/RelatedPartiesScheduleofTransactionswithRelatedPartiesDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_ShortTermBenefitsMember" xlink:label="synx_ShortTermBenefitsMember_1415" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_BenefitsToSeniorOfficersMember" xlink:label="synx_BenefitsToSeniorOfficersMember_1416" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_BenefitsToRelatedPartiesMember" xlink:label="synx_BenefitsToRelatedPartiesMember_1417" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_PayrollAndRelatedExpensesInRespectOfEmployedRelatedPartiesMember" xlink:label="synx_PayrollAndRelatedExpensesInRespectOfEmployedRelatedPartiesMember_1418" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_AccountsPayableAndAccrualsMember" xlink:label="synx_AccountsPayableAndAccrualsMember_1419" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_BalancesWithRelatedPartiesMember" xlink:label="synx_BalancesWithRelatedPartiesMember_1420" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesDomain" xlink:label="ifrs-full_CategoriesOfRelatedPartiesDomain_1262" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesTable" xlink:label="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesTable_1188" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesAxis" xlink:label="ifrs-full_CategoriesOfRelatedPartiesAxis_1189" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems" xlink:label="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems_1191" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_AmountsPayableRelatedPartyTransactions" xlink:label="ifrs-full_AmountsPayableRelatedPartyTransactions_1411" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ShorttermEmployeeBenefitsExpense" xlink:label="ifrs-full_ShorttermEmployeeBenefitsExpense_1412" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ClassesOfFinancialInstrumentsAxis" xlink:label="ifrs-full_ClassesOfFinancialInstrumentsAxis_1413" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ClassesOfFinancialInstrumentsDomain" xlink:label="ifrs-full_ClassesOfFinancialInstrumentsDomain_1414" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_NumberOfRecipients" xlink:label="synx_NumberOfRecipients_1421" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_NumberOfRelatedParties" xlink:label="synx_NumberOfRelatedParties_1422" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesDomain" xlink:label="ifrs-full_CategoriesOfRelatedPartiesDomain_1262_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ClassesOfFinancialInstrumentsDomain" xlink:label="ifrs-full_ClassesOfFinancialInstrumentsDomain_1414_default" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ClassesOfFinancialInstrumentsDomain_1414" xlink:to="synx_ShortTermBenefitsMember_1415" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_CategoriesOfRelatedPartiesDomain_1262" xlink:to="synx_BenefitsToSeniorOfficersMember_1416" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_CategoriesOfRelatedPartiesDomain_1262" xlink:to="synx_BenefitsToRelatedPartiesMember_1417" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ClassesOfFinancialInstrumentsDomain_1414" xlink:to="synx_PayrollAndRelatedExpensesInRespectOfEmployedRelatedPartiesMember_1418" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ClassesOfFinancialInstrumentsDomain_1414" xlink:to="synx_AccountsPayableAndAccrualsMember_1419" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_CategoriesOfRelatedPartiesDomain_1262" xlink:to="synx_BalancesWithRelatedPartiesMember_1420" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_CategoriesOfRelatedPartiesAxis_1189" xlink:to="ifrs-full_CategoriesOfRelatedPartiesDomain_1262" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems_1191" xlink:to="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesTable_1188" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesTable_1188" xlink:to="ifrs-full_CategoriesOfRelatedPartiesAxis_1189" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems_1191" xlink:to="ifrs-full_AmountsPayableRelatedPartyTransactions_1411" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems_1191" xlink:to="ifrs-full_ShorttermEmployeeBenefitsExpense_1412" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesTable_1188" xlink:to="ifrs-full_ClassesOfFinancialInstrumentsAxis_1413" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_ClassesOfFinancialInstrumentsAxis_1413" xlink:to="ifrs-full_ClassesOfFinancialInstrumentsDomain_1414" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems_1191" xlink:to="synx_NumberOfRecipients_1421" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems_1191" xlink:to="synx_NumberOfRelatedParties_1422" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_CategoriesOfRelatedPartiesAxis_1189" xlink:to="ifrs-full_CategoriesOfRelatedPartiesDomain_1262_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_ClassesOfFinancialInstrumentsAxis_1413" xlink:to="ifrs-full_ClassesOfFinancialInstrumentsDomain_1414_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://silynxcom.com/20260630/role/GeneralDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_InitialPublicOfferingMember" xlink:label="synx_InitialPublicOfferingMember_1218" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesDomain" xlink:label="ifrs-full_CategoriesOfRelatedPartiesDomain_1265" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ProfitLoss" xlink:label="ifrs-full_ProfitLoss_1306" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_RetainedEarnings" xlink:label="ifrs-full_RetainedEarnings_1309" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_OtherCashAndCashEquivalents" xlink:label="ifrs-full_OtherCashAndCashEquivalents_1310" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_WorkingCapital" xlink:label="synx_WorkingCapital_1311" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_GeneralLineItems" xlink:label="synx_GeneralLineItems_1223" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_NumberOfSharesIssued" xlink:label="ifrs-full_NumberOfSharesIssued_1224" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ParValuePerShare" xlink:label="ifrs-full_ParValuePerShare_1225" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_GrossProceeds" xlink:label="synx_GrossProceeds_1226" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_GeneralTable" xlink:label="synx_GeneralTable_1216" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesAxis" xlink:label="ifrs-full_CategoriesOfRelatedPartiesAxis_1217" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesDomain" xlink:label="ifrs-full_CategoriesOfRelatedPartiesDomain_1265_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_CategoriesOfRelatedPartiesDomain_1265" xlink:to="synx_InitialPublicOfferingMember_1218" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_CategoriesOfRelatedPartiesAxis_1217" xlink:to="ifrs-full_CategoriesOfRelatedPartiesDomain_1265" />
    <link:definitionArc xlink:type="arc" order="57.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="synx_GeneralLineItems_1223" xlink:to="ifrs-full_ProfitLoss_1306" />
    <link:definitionArc xlink:type="arc" order="60.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="synx_GeneralLineItems_1223" xlink:to="ifrs-full_RetainedEarnings_1309" />
    <link:definitionArc xlink:type="arc" order="61.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="synx_GeneralLineItems_1223" xlink:to="ifrs-full_OtherCashAndCashEquivalents_1310" />
    <link:definitionArc xlink:type="arc" order="62.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="synx_GeneralLineItems_1223" xlink:to="synx_WorkingCapital_1311" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="synx_GeneralLineItems_1223" xlink:to="ifrs-full_NumberOfSharesIssued_1224" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="synx_GeneralLineItems_1223" xlink:to="ifrs-full_ParValuePerShare_1225" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="synx_GeneralLineItems_1223" xlink:to="synx_GrossProceeds_1226" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="synx_GeneralLineItems_1223" xlink:to="synx_GeneralTable_1216" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="synx_GeneralTable_1216" xlink:to="ifrs-full_CategoriesOfRelatedPartiesAxis_1217" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_CategoriesOfRelatedPartiesAxis_1217" xlink:to="ifrs-full_CategoriesOfRelatedPartiesDomain_1265_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://silynxcom.com/20260630/role/RevenueScheduleofRevenueDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_InEarHeadsetSystemsMember" xlink:label="synx_InEarHeadsetSystemsMember_1169" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_SSTHeadsetSystemsMember" xlink:label="synx_SSTHeadsetSystemsMember_1170" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_COUNTRYILMember" xlink:label="synx_COUNTRYILMember_1162" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EuropeMember" xlink:label="srt_EuropeMember_1163" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AsiaMember" xlink:label="srt_AsiaMember_1164" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_COUNTRYUSMember" xlink:label="synx_COUNTRYUSMember_1165" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_CustomerOneMember" xlink:label="synx_CustomerOneMember_1393" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_CustomerTwoMember" xlink:label="synx_CustomerTwoMember_1394" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_OtherGeographyMember" xlink:label="synx_OtherGeographyMember_1400" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_OtherProductMember" xlink:label="synx_OtherProductMember_1401" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems" xlink:label="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems_1172" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_Revenue" xlink:label="ifrs-full_Revenue_1174" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ProductsAndServicesDomain" xlink:label="ifrs-full_ProductsAndServicesDomain_1168" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_GeographicalAreasAxis" xlink:label="ifrs-full_GeographicalAreasAxis_1160" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_GeographicalAreasDomain" xlink:label="ifrs-full_GeographicalAreasDomain_1161" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ProductsAndServicesAxis" xlink:label="ifrs-full_ProductsAndServicesAxis_1167" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersTable" xlink:label="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersTable_1159" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_TypesOfCustomersAxis" xlink:label="ifrs-full_TypesOfCustomersAxis_1391" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_TypesOfCustomersDomain" xlink:label="ifrs-full_TypesOfCustomersDomain_1392" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_RevenueFromContractsWithCustomers" xlink:label="ifrs-full_RevenueFromContractsWithCustomers_1395" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_TradeReceivables" xlink:label="ifrs-full_TradeReceivables_1396" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ProductsAndServicesDomain" xlink:label="ifrs-full_ProductsAndServicesDomain_1168_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_GeographicalAreasDomain" xlink:label="ifrs-full_GeographicalAreasDomain_1161_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_TypesOfCustomersDomain" xlink:label="ifrs-full_TypesOfCustomersDomain_1392_default" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ProductsAndServicesDomain_1168" xlink:to="synx_InEarHeadsetSystemsMember_1169" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ProductsAndServicesDomain_1168" xlink:to="synx_SSTHeadsetSystemsMember_1170" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_GeographicalAreasDomain_1161" xlink:to="synx_COUNTRYILMember_1162" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_GeographicalAreasDomain_1161" xlink:to="srt_EuropeMember_1163" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_GeographicalAreasDomain_1161" xlink:to="srt_AsiaMember_1164" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_GeographicalAreasDomain_1161" xlink:to="synx_COUNTRYUSMember_1165" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_TypesOfCustomersDomain_1392" xlink:to="synx_CustomerOneMember_1393" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_TypesOfCustomersDomain_1392" xlink:to="synx_CustomerTwoMember_1394" />
    <link:definitionArc xlink:type="arc" order="108.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_GeographicalAreasDomain_1161" xlink:to="synx_OtherGeographyMember_1400" />
    <link:definitionArc xlink:type="arc" order="109.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ProductsAndServicesDomain_1168" xlink:to="synx_OtherProductMember_1401" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems_1172" xlink:to="ifrs-full_Revenue_1174" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_ProductsAndServicesAxis_1167" xlink:to="ifrs-full_ProductsAndServicesDomain_1168" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersTable_1159" xlink:to="ifrs-full_GeographicalAreasAxis_1160" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_GeographicalAreasAxis_1160" xlink:to="ifrs-full_GeographicalAreasDomain_1161" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersTable_1159" xlink:to="ifrs-full_ProductsAndServicesAxis_1167" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems_1172" xlink:to="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersTable_1159" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersTable_1159" xlink:to="ifrs-full_TypesOfCustomersAxis_1391" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_TypesOfCustomersAxis_1391" xlink:to="ifrs-full_TypesOfCustomersDomain_1392" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems_1172" xlink:to="ifrs-full_RevenueFromContractsWithCustomers_1395" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems_1172" xlink:to="ifrs-full_TradeReceivables_1396" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_ProductsAndServicesAxis_1167" xlink:to="ifrs-full_ProductsAndServicesDomain_1168_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_GeographicalAreasAxis_1160" xlink:to="ifrs-full_GeographicalAreasDomain_1161_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_TypesOfCustomersAxis_1391" xlink:to="ifrs-full_TypesOfCustomersDomain_1392_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://silynxcom.com/20260630/role/ShareBasedPaymentDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ShareOptionsMember" xlink:label="ifrs-full_ShareOptionsMember_1379" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_NumberOfShareOptionsGrantedInSharebasedPaymentArrangement" xlink:label="ifrs-full_NumberOfShareOptionsGrantedInSharebasedPaymentArrangement_1287" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_OptionExercisableRatio" xlink:label="synx_OptionExercisableRatio_1294" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_ShareBasedPaymentVestingPeriod" xlink:label="synx_ShareBasedPaymentVestingPeriod_1295" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_FairValueOfAforesaidOptions" xlink:label="synx_FairValueOfAforesaidOptions_1296" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementTable" xlink:label="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementTable_1376" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_TypesOfSharebasedPaymentArrangementsAxis" xlink:label="ifrs-full_TypesOfSharebasedPaymentArrangementsAxis_1377" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_TypesOfSharebasedPaymentArrangementsDomain" xlink:label="ifrs-full_TypesOfSharebasedPaymentArrangementsDomain_1378" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems" xlink:label="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems_1380" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement2019" xlink:label="ifrs-full_WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement2019_1390" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_TypesOfSharebasedPaymentArrangementsDomain" xlink:label="ifrs-full_TypesOfSharebasedPaymentArrangementsDomain_1378_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_TypesOfSharebasedPaymentArrangementsDomain_1378" xlink:to="ifrs-full_ShareOptionsMember_1379" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems_1380" xlink:to="ifrs-full_NumberOfShareOptionsGrantedInSharebasedPaymentArrangement_1287" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems_1380" xlink:to="synx_OptionExercisableRatio_1294" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems_1380" xlink:to="synx_ShareBasedPaymentVestingPeriod_1295" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems_1380" xlink:to="synx_FairValueOfAforesaidOptions_1296" />
    <link:definitionArc xlink:type="arc" order="101.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems_1380" xlink:to="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementTable_1376" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementTable_1376" xlink:to="ifrs-full_TypesOfSharebasedPaymentArrangementsAxis_1377" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_TypesOfSharebasedPaymentArrangementsAxis_1377" xlink:to="ifrs-full_TypesOfSharebasedPaymentArrangementsDomain_1378" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems_1380" xlink:to="ifrs-full_WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement2019_1390" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_TypesOfSharebasedPaymentArrangementsAxis_1377" xlink:to="ifrs-full_TypesOfSharebasedPaymentArrangementsDomain_1378_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://silynxcom.com/20260630/role/ShareBasedPaymentScheduleofFairValueoftheOptionsDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_BlackScholesOptionPricingModelMember" xlink:label="synx_BlackScholesOptionPricingModelMember_1406" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_WeightedAverageSharePriceShareOptionsGranted2019" xlink:label="ifrs-full_WeightedAverageSharePriceShareOptionsGranted2019_1304" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ExercisePriceShareOptionsGranted2019" xlink:label="ifrs-full_ExercisePriceShareOptionsGranted2019_1305" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DescriptionOfExpectedVolatilityShareOptionsGranted" xlink:label="ifrs-full_DescriptionOfExpectedVolatilityShareOptionsGranted_1307" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DescriptionOfOptionLifeShareOptionsGranted" xlink:label="ifrs-full_DescriptionOfOptionLifeShareOptionsGranted_1308" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DescriptionOfRiskFreeInterestRateShareOptionsGranted" xlink:label="ifrs-full_DescriptionOfRiskFreeInterestRateShareOptionsGranted_1313" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsTable" xlink:label="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsTable_1402" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems" xlink:label="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems_1403" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ValuationTechniquesUsedInFairValueMeasurementAxis" xlink:label="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementAxis_1404" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ValuationTechniquesUsedInFairValueMeasurementDomain" xlink:label="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementDomain_1405" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ValuationTechniquesUsedInFairValueMeasurementDomain" xlink:label="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementDomain_1405_default" />
    <link:definitionArc xlink:type="arc" order="114.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementDomain_1405" xlink:to="synx_BlackScholesOptionPricingModelMember_1406" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems_1403" xlink:to="ifrs-full_WeightedAverageSharePriceShareOptionsGranted2019_1304" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems_1403" xlink:to="ifrs-full_ExercisePriceShareOptionsGranted2019_1305" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems_1403" xlink:to="ifrs-full_DescriptionOfExpectedVolatilityShareOptionsGranted_1307" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems_1403" xlink:to="ifrs-full_DescriptionOfOptionLifeShareOptionsGranted_1308" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems_1403" xlink:to="ifrs-full_DescriptionOfRiskFreeInterestRateShareOptionsGranted_1313" />
    <link:definitionArc xlink:type="arc" order="110.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsLineItems_1403" xlink:to="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsTable_1402" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfNumberAndWeightedAverageRemainingContractualLifeOfOutstandingShareOptionsTable_1402" xlink:to="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementAxis_1404" />
    <link:definitionArc xlink:type="arc" order="113.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementAxis_1404" xlink:to="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementDomain_1405" />
    <link:definitionArc xlink:type="arc" order="113.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementAxis_1404" xlink:to="ifrs-full_ValuationTechniquesUsedInFairValueMeasurementDomain_1405_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://silynxcom.com/20260630/role/SubsequentEventsDetails" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_SilynxCommunicationsIncMember" xlink:label="synx_SilynxCommunicationsIncMember_1341" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_RuthNirMember" xlink:label="synx_RuthNirMember_1344" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_GalNirKleinAndNirKleinMember" xlink:label="synx_GalNirKleinAndNirKleinMember_1349" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_MajorOrdinaryShareTransactionsMember" xlink:label="ifrs-full_MajorOrdinaryShareTransactionsMember_1423" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_IssuedCapital" xlink:label="ifrs-full_IssuedCapital_1325" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodTable" xlink:label="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodTable_1327" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_NonadjustingEventsAfterReportingPeriodAxis" xlink:label="ifrs-full_NonadjustingEventsAfterReportingPeriodAxis_1328" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_NonadjustingEventsAfterReportingPeriodDomain" xlink:label="ifrs-full_NonadjustingEventsAfterReportingPeriodDomain_1329" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems" xlink:label="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesAxis" xlink:label="ifrs-full_CategoriesOfRelatedPartiesAxis_1338" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesDomain" xlink:label="ifrs-full_CategoriesOfRelatedPartiesDomain_1339" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_PercentageOfRetainedShares" xlink:label="synx_PercentageOfRetainedShares_1345" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_PercentageOfEquityInterest" xlink:label="synx_PercentageOfEquityInterest_1347" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_EquityInterestsOfAcquirer" xlink:label="ifrs-full_EquityInterestsOfAcquirer_1348" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_SharesRetained" xlink:label="synx_SharesRetained_1424" />
    <link:loc xlink:type="locator" xlink:href="synx-20260630.xsd#synx_ClaimedMonetaryDamages" xlink:label="synx_ClaimedMonetaryDamages_1425" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_NonadjustingEventsAfterReportingPeriodDomain" xlink:label="ifrs-full_NonadjustingEventsAfterReportingPeriodDomain_1329_default" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_CategoriesOfRelatedPartiesDomain" xlink:label="ifrs-full_CategoriesOfRelatedPartiesDomain_1339_default" />
    <link:definitionArc xlink:type="arc" order="85.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_CategoriesOfRelatedPartiesDomain_1339" xlink:to="synx_SilynxCommunicationsIncMember_1341" />
    <link:definitionArc xlink:type="arc" order="88.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_CategoriesOfRelatedPartiesDomain_1339" xlink:to="synx_RuthNirMember_1344" />
    <link:definitionArc xlink:type="arc" order="93.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_CategoriesOfRelatedPartiesDomain_1339" xlink:to="synx_GalNirKleinAndNirKleinMember_1349" />
    <link:definitionArc xlink:type="arc" order="119.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_NonadjustingEventsAfterReportingPeriodDomain_1329" xlink:to="ifrs-full_MajorOrdinaryShareTransactionsMember_1423" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" xlink:to="ifrs-full_IssuedCapital_1325" />
    <link:definitionArc xlink:type="arc" order="71.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" xlink:to="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodTable_1327" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodTable_1327" xlink:to="ifrs-full_NonadjustingEventsAfterReportingPeriodAxis_1328" />
    <link:definitionArc xlink:type="arc" order="73.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_NonadjustingEventsAfterReportingPeriodAxis_1328" xlink:to="ifrs-full_NonadjustingEventsAfterReportingPeriodDomain_1329" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodTable_1327" xlink:to="ifrs-full_CategoriesOfRelatedPartiesAxis_1338" />
    <link:definitionArc xlink:type="arc" order="83.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_CategoriesOfRelatedPartiesAxis_1338" xlink:to="ifrs-full_CategoriesOfRelatedPartiesDomain_1339" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" xlink:to="synx_PercentageOfRetainedShares_1345" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" xlink:to="synx_PercentageOfEquityInterest_1347" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" xlink:to="ifrs-full_EquityInterestsOfAcquirer_1348" />
    <link:definitionArc xlink:type="arc" order="17.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" xlink:to="synx_SharesRetained_1424" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems_1336" xlink:to="synx_ClaimedMonetaryDamages_1425" />
    <link:definitionArc xlink:type="arc" order="73.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_NonadjustingEventsAfterReportingPeriodAxis_1328" xlink:to="ifrs-full_NonadjustingEventsAfterReportingPeriodDomain_1329_default" />
    <link:definitionArc xlink:type="arc" order="83.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_CategoriesOfRelatedPartiesAxis_1338" xlink:to="ifrs-full_CategoriesOfRelatedPartiesDomain_1339_default" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://silynxcom.com/20260630/role/UnauditedInterimCondensedConsolidatedStatementsofChangesinShareholdersEquity" xlink:type="extended" xlink:title="definitionLink">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_SharePremiumMember" xlink:label="ifrs-full_SharePremiumMember_1057" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_OtherReservesMember" xlink:label="ifrs-full_OtherReservesMember_1058" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_RetainedEarningsMember" xlink:label="ifrs-full_RetainedEarningsMember_1059" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_StatementOfChangesInEquityTable" xlink:label="ifrs-full_StatementOfChangesInEquityTable_1055" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ComponentsOfEquityAxis" xlink:label="ifrs-full_ComponentsOfEquityAxis_1056" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_IncreaseDecreaseThroughExerciseOfOptions" xlink:label="ifrs-full_IncreaseDecreaseThroughExerciseOfOptions_1063" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_IssueOfEquity" xlink:label="ifrs-full_IssueOfEquity_1064" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_IncreaseDecreaseThroughSharebasedPaymentTransactions" xlink:label="ifrs-full_IncreaseDecreaseThroughSharebasedPaymentTransactions_1066" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ComprehensiveIncome" xlink:label="ifrs-full_ComprehensiveIncome_1068" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_Equity" xlink:label="ifrs-full_Equity_1069" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ComponentsOfEquityDomain" xlink:label="ifrs-full_ComponentsOfEquityDomain_1060" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_StatementOfChangesInEquityLineItems" xlink:label="ifrs-full_StatementOfChangesInEquityLineItems_1061" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.ifrs.org/taxonomy/2025-03-27/full_ifrs/full_ifrs-cor_2025-03-27.xsd#ifrs-full_ComponentsOfEquityDomain" xlink:label="ifrs-full_ComponentsOfEquityDomain_1060_default" />
    <link:definitionArc xlink:type="arc" order="10.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ComponentsOfEquityDomain_1060" xlink:to="ifrs-full_SharePremiumMember_1057" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ComponentsOfEquityDomain_1060" xlink:to="ifrs-full_OtherReservesMember_1058" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_ComponentsOfEquityDomain_1060" xlink:to="ifrs-full_RetainedEarningsMember_1059" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="true" use="optional" xbrldt:contextElement="segment" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems_1061" xlink:to="ifrs-full_StatementOfChangesInEquityTable_1055" />
    <link:definitionArc xlink:type="arc" order="11.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ifrs-full_StatementOfChangesInEquityTable_1055" xlink:to="ifrs-full_ComponentsOfEquityAxis_1056" />
    <link:definitionArc xlink:type="arc" order="12.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems_1061" xlink:to="ifrs-full_IncreaseDecreaseThroughExerciseOfOptions_1063" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems_1061" xlink:to="ifrs-full_IssueOfEquity_1064" />
    <link:definitionArc xlink:type="arc" order="14.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems_1061" xlink:to="ifrs-full_IncreaseDecreaseThroughSharebasedPaymentTransactions_1066" />
    <link:definitionArc xlink:type="arc" order="15.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems_1061" xlink:to="ifrs-full_ComprehensiveIncome_1068" />
    <link:definitionArc xlink:type="arc" order="16.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ifrs-full_StatementOfChangesInEquityLineItems_1061" xlink:to="ifrs-full_Equity_1069" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ifrs-full_ComponentsOfEquityAxis_1056" xlink:to="ifrs-full_ComponentsOfEquityDomain_1060" />
    <link:definitionArc xlink:type="arc" order="13.00000" priority="1" xbrldt:closed="false" use="optional" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ifrs-full_ComponentsOfEquityAxis_1056" xlink:to="ifrs-full_ComponentsOfEquityDomain_1060_default" />
  </link:definitionLink>
</link:linkbase>
