/ə'kɪli:z; ə`kɪliz/
n (idm 习语) an/one's Achilles' `heel weak or vulnerable point; fault, esp in sb's character, which can lead to his downfall 致命弱点; （尤指某人个性中可导致一败涂地的）缺陷
*Vanity is his Achilles' heel. 虚荣自负是他的致命伤.

A·chil·les
in ancient Greek stories, a hero who was protected by magic so that the only place where he could be hurt was his heel