/ Dictionary / Index A ammonium hydroxide: Meaning and Definition of Find definitions for: ammo'nium hydrox'ide Pronunciation: [key] — Chem. Chem. a basic compound, NHOH, existing only in solution, formed by dissolving ammonia gas in water. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ammonium cyanate ammonium lactate Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language