Wordnet 3.0
NOUN (1)
1.
a mythical Greek hero of the Iliad;
a foremost Greek warrior at the siege of Troy;
when he was a baby his mother tried to make him immortal by bathing him in a magical river but the heel by which she held him remained vulnerable--his `Achilles' heel';
The Collaborative International Dictionary of English v.0.48:
Achilles \Achilles\ n.
1. a mythical Greek hero of the Iliad; a foremost Greek
warrior at the seige of Troy.
[WordNet 1.5]
WordNet (r) 3.0 (2006):
Achilles
n 1: a mythical Greek hero of the Iliad; a foremost Greek
warrior at the siege of Troy; when he was a baby his mother
tried to make him immortal by bathing him in a magical
river but the heel by which she held him remained
vulnerable--his `Achilles' heel'