- thigh (n.)
- Old English þeoh, þeh, from Proto-Germanic *theukhom (cf. Old Frisian thiach, Old Dutch thio, Dutch dij, Old Norse þjo, Old High German dioh), from PIE *teuk- from root *teu- "to swell" (cf. Lithuanian taukas, Old Church Slavonic tuku, Russian tuku "fat of animals;" Lithuanian tukti "to become fat;" Greek tylos "callus, lump," tymbos "burial mound, grave, tomb;" Old Irish ton "rump;" Latin tumere "to swell," tumulus "raised heap of earth," tumor "a swelling;" Middle Irish tomm "a small hill," Welsh tom "mound"). Thus thigh is literally "the thick or fat part of the leg."