ALL meanings of red mercuric oxide
red mer·cu·ric ox·ide
R r - noun red mercuric oxide a slightly crystalline, water-soluble, poisonous compound, HgO, occurring as a coarse, orange-red powder (red mercuric oxide) or as a fine, orange-yellow powder (yellow mercuric oxide) used chiefly as a pigment in paints and as an antiseptic in pharmaceuticals. 1