rump

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The fleshy hindquarters of an animal.
• noun A cut of beef or veal from the rump.
• noun The buttocks.
• noun The part of a bird's back nearest the tail.
• noun The last or inferior part.
• noun A legislature having only a small part of its original membership and therefore being unrepresentative or lacking in authority.

from The Century Dictionary.

• To turn one's back upon.
• noun The tail-end of an animal; the hinder parts; the backside or buttocks; technically, the gluteal or uropygial region; the uropygium. See sacrum and uropygium.
• noun Figuratively. the fag-end of a thing.

from the GNU version of the Collaborative International Dictionary of English.

• noun The end of the backbone of an animal, with the parts adjacent; the buttock or buttocks.
• noun Among butchers, the piece of beef between the sirloin and the aitchbone piece. See Illust. of Beef.
• noun The hind or tail end; a fag-end; a remnant.
• noun (Eng. Hist.) the remnant of the Long Parliament after the expulsion by Cromwell in 1648 of those who opposed his purposes. It was dissolved by Cromwell in 1653, but twice revived for brief sessions, ending finally in 1659.
• noun a beefsteak from the rump.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun the hindquarters of an animal
• noun a cut of meat from the rump
• noun the buttocks
• noun remnant, as in rump parliament

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the fleshy part of the human body that you sit on
• noun fleshy hindquarters; behind the loin and above the round
• noun the part of an animal that corresponds to the human buttocks