/ Dictionary / Index G gum ammoniac: Meaning and Definition of Find definitions for: gum' ammo'niac Pronunciation: [key] a brownish-yellow gum resin, having an acrid taste, occurring in tearlike fragments from a plant, Dorema ammoniacum, of western Asia: used in porcelain ceramics and in medicine as an expectorant and counterirritant. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. gum gum arabic Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language