/ Dictionary / Index B buttock: Meaning and Definition of Find definitions for: but•tock Pronunciation: (but'uk), [key] — n. Usually, (in humans) either of the two fleshy protuberances forming the lower and back part of the trunk. (in animals) the rump. Sometimes,the aftermost portion of a hull above the water line and in front of the rudder, merging with the run below the water line. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: buttock (Thesaurus) buttle button Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language