/ Dictionary / Index M mercuric oxide: Meaning and Definition of Find definitions for: mercu'ric ox'ide Pronunciation: [key] a slightly crystalline, water-soluble, poisonous compound, HgO, occurring as a coarse, orange-red powderor as a fine, orange-yellow powder: used chiefly as a pigment in paints and as an antiseptic in pharmaceuticals. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mercuric chloride mercuric sulfide Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language