/ Dictionary / Index T trinomial: Meaning and Definition of Find definitions for: tri•no•mi•al Pronunciation: (trī-nō'mē-ul), [key] — adj. consisting of or pertaining to three terms. pertaining to a scientific name comprising three terms, as of genus, species, and subspecies or variety. characterized by the use of such names. —n. an expression that is a sum or difference of three terms, as 3x + 2y + z or 3x + 2x + x. a trinomial name, as Rosa gallica pumila. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trinodal trinucleotide Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language