/ Dictionary / Index T triangular: Meaning and Definition of Find definitions for: tri•an•gu•lar Pronunciation: (trī-ang'gyu-lur), [key] — adj. pertaining to or having the form of a triangle; three-cornered. having a triangle as base or cross section: a triangular prism. comprising three parts or elements; triple. pertaining to or involving a group of three, as three persons, parties, or things. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: triangular (Thesaurus) triangle inequality triangular matrix Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language