n. 半边臀部, 屁股, 船尾突出部

vt. 过背摔

[医] 臀

[ noun ]
either of the two large fleshy masses of muscular tissue that form the human rump
<noun.body>

Buttock \But"tock\, n. [From {Butt} an end.]
1. The part at the back of the hip, which, in man, forms one
of the rounded protuberances on which he sits; the rump.
Often used in the plural -- see {buttocks}.

Syn: cheek.

2. (Naut.) The convexity of a ship behind, under the stern.
--Mar. Dict.