buttock Meaning, Definition & Usage

  1. noun either of the two large fleshy masses of muscular tissue that form the human rump
    cheek.

WordNet

But"tock noun
Etymology
From Butt an end.
Definitions
  1. The part at the back of the hip, which, in man, forms one of the rounded protuberances on which he sits; the rump.
  2. (Naut.) The convexity of a ship behind, under the stern. Mar. Dict.

Webster 1913