/ Dictionary / Index T trimotor: Meaning and Definition of Find definitions for: tri•mo•tor Pronunciation: (trī'mō"tur), [key] — n. an airplane or other vehicle that has three motors. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trimorphism trim rail Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language