/ Dictionary / Index T trimaran: Meaning and Definition of Find definitions for: tri•ma•ran Pronunciation: (trī'mu-ran"), [key] — n. a vessel similar to a catamaran but having three separate hulls. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: trimaran (Thesaurus) trim trim die Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language