Thigh \Thigh\ (th[imac]), n. [OE. thi, [thorn]ih, [thorn]eh, AS. [thorn]e['o]h; akin to OFries. thiach, D. dij, dije, OHG. dioh, thioh, Icel. [thorn]j[=o] thigh, rump, and probably to Lith. taukas fat of animals, tukti to become fat, Russ. tuke fat of animals. [root]56.]

1. (Anat.) The proximal segment of the hind limb between the knee and the trunk. See Femur.

2. (Zo["o]l.) The coxa, or femur, of an insect.

Thigh bone (Anat.), the femur.

Source: Webster's Revised Unabridged Dictionary (1913)