/ Dictionary / Index R reaction formation: Meaning and Definition of Find definitions for: reac'tion forma"tion Pronunciation: [key] — Psychoanal. Psychoanal. a behavioral tendency developed in direct opposition to a repressed impulse. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. reaction engine reaction time Related Content Daily Word Quiz: diligent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language