/ Dictionary / Index I interactant: Meaning and Definition of Find definitions for: in•ter•ac•tant Pronunciation: (in"tur-ak'tunt), [key] — n. a person or thing that interacts. reactant (def. 2). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. interact interaction Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language