/ Dictionary / Index R rainout: Meaning and Definition of Find definitions for: rain•out Pronunciation: (rān'out"), [key] — n. a contest, performance, or the like, that has been rained out. Also calledthe removal of radioactive particles or other foreign substances from the atmosphere by precipitation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rain or shine rainproof Related Content Daily Word Quiz: supine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language