Alluding to these legends, the term "Achilles' heel" has come to mean a point of weakness which can lead to downfall, especially in someone or something with an otherwise strong constitution.
ɐlˈuːdɪŋ tə ðiːz lˈɛdʒəndz, ðə tˈɜːm "ɐkˈɪliːz hˈiːl" hɐz kˈʌm tə mˈiːn ɐ pˈɔɪnt ʌv wˈiːknəs wˌɪtʃ kæn lˈiːd tə dˈaʊnfɔːl, ɪspˈɛʃəli ɪn sˈʌmwʌn ɔːɹ sˈʌmθɪŋ wɪð ɐn ˈʌðɚwˌaɪz stɹˈɔŋ kˌɑːnstɪtˈuːʃən.