/ Dictionary / Index C coefficient of restitution: Meaning and Definition of Find definitions for: coeffi'cient of restitu'tion Pronunciation: [key] — Physics. Physics. the ratio of the relative velocity after impact to the relative velocity before the impact of two colliding bodies, equal to 1 for an elastic collision and 0 for an inelastic collision. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. coefficient of performance coefficient of viscosity Related Content Daily Word Quiz: agitated Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language