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Webster 1913 Edition
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.