What does achilles’ tendon mean?
The definition of achilles’ tendon
A*chil”les’ ten”don, n.
Etym: [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.