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mercuric oxide

noun Chemistry.
  1. 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.
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British Dictionary definitions for mercuric oxide

mercuric oxide

noun
  1. a soluble poisonous substance existing in red and yellow powdered forms: used as pigments. Formula: HgOSystematic name: mercury(II) oxide
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012