rump

American Heritage® Dictionary of the English Language, Fourth Edition

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

Century Dictionary and Cyclopedia

1. n. 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.
2. n. Figuratively. the fag-end of a thing. Specifically [capitalized], in English history, the fag-end of the Long Parliament, after the expulsion of the majority of its members, or Pride's Purge, by Cromwell in 1648. The Rump was forcibly dissolved by Cromwell in 1653, but was afterward reinstated on two different occasions for brief periods. Also called Rump Parliament.
3. To turn one's back upon.

Wiktionary

1. n. the hindquarters of an animal
2. n. a cut of meat from the rump
3. n. the buttocks
4. n. remnant, as in rump parliament

GNU Webster's 1913

1. n. The end of the backbone of an animal, with the parts adjacent; the buttock or buttocks.
2. n. Among butchers, the piece of beef between the sirloin and the aitchbone piece. See Illust. of Beef.
3. n. The hind or tail end; a fag-end; a remnant.

WordNet 3.0

1. n. the fleshy part of the human body that you sit on
2. n. fleshy hindquarters; behind the loin and above the round
3. n. the part of an animal that corresponds to the human buttocks