- either of the two fleshy, rounded parts at the back of the hips; either half of the rump
- [pl.] the rump
Origin of buttockMiddle English buttok from Old English buttuc, end, short piece of land: see butt and -ock
- a. Either of the two rounded prominences on the human torso that are posterior to the hips and formed by the gluteal muscles and underlying structures.b. The analogous part of the body on certain mammals.
- buttocks The rear pelvic area of the human body.
Origin of buttockMiddle English from Old English buttuc strip of land, end ; see bhau- in Indo-European roots.
The plural form is usually used in the singular sense for a single person's posterior, often called butt. It is rarer to refer to only a single buttock, which is then usually specified as left or right.
Probably from Old English buttuc (“end, short piece of land”), attested since circa 1300, diminutive form of what is presumedly the Old English precursor of butt.