/ Dictionary / Index T trimolecular: Meaning and Definition of Find definitions for: tri•mo•lec•u•lar Pronunciation: (trī"mu-lek'yu-lur), [key] — adj. Chem. pertaining to or having three molecules. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trimodal trimonthly Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language