/ Dictionary / Index R radiation pressure: Meaning and Definition of Find definitions for: radia'tion pres"sure Pronunciation: [key] — Physics. Physics. the pressure exerted on a surface by electromagnetic radiation or by sound waves. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. radiation potential radiation sickness Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language