buttock

[buht-uh k] /ˈbʌt ək/
noun
1.
Usually, buttocks.
  1. (in humans) either of the two fleshy protuberances forming the lower and back part of the trunk.
  2. (in animals) the rump.
2.
Sometimes, buttocks. Nautical. the aftermost portion of a hull above the water line and in front of the rudder, merging with the run below the water line.
Origin
before 1000; Middle English buttok, Old English buttuc. See butt1, -ock
Related forms
buttocked, adjective
British Dictionary definitions for buttocks

buttock

/ˈbʌtək/
noun
1.
either of the two large fleshy masses of thick muscular tissue that form the human rump See also gluteus related adjectives gluteal natal
2.
the analogous part in some mammals
Word Origin
C13: perhaps from Old English buttuc round slope, diminutive of butt (unattested) strip of land; see butt1-ock
Word Origin and History for buttocks
n.

late 13c., probably related to Old English buttuc "end, short piece of land" (see butt (n.1)).

buttock

n.

late 13c., singular of buttocks (q.v.).

buttocks in Medicine

buttock but·tock (bŭt'ək)
n.

  1. 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.

  2. buttocks The rear pelvic area of the human body.