/ Dictionary / Index T trilateral: Meaning and Definition of Find definitions for: tri•lat•er•al Pronunciation: (trī-lat'ur-ul), [key] — adj. having three sides. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: trilateral (Thesaurus) Trilafon trilateration Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language