/ Dictionary / Index A acid precipitation: Meaning and Definition of Find definitions for: ac'id precipita'tion Pronunciation: [key] meteorological precipitation that is relatively acidic. Cf. acid rain. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. acid phosphate acid radical Related Content Daily Word Quiz: pudgy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language