From The Collaborative International Dictionary of English v.0.48 [gcide]:
Achilles' tendon \A*chil"les' ten"don\, noun [L. Achillis tendo.] (Anat.) The strong tendon formed of the united tendons of the large muscles in the calf of the leg, an inserted into the bone of the heel; -- so called from the mythological account of Achilles being held by the heel when dipped in the River Styx.
From WordNet (r) 3.0 (2006) [wn]:
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