/ Dictionary / Index T triatomic: Meaning and Definition of Find definitions for: tri•a•tom•ic Pronunciation: (trī"u-tom'ik), [key] — adj. Chem. having three atoms in a molecule. having three replaceable hydrogen atoms. having three replaceable hydroxyl groups. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. triatic stay triaxial Related Content Daily Word Quiz: wizened Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language