/ Dictionary / Index A antrum: Meaning and Definition of Find definitions for: an•trum Pronunciation: (an'trum), [key] — pl. -tra a cavity in a body organ, esp. a bone. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: antrum (Thesaurus) antrorse antshrike Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language