osmium tetroxide

noun Chemistry.

1. a crystalline or amorphous, colorless, poisonous compound, OsO4, soluble in water, alcohol, and ether: used for microscopic staining, in photography, and as a catalyst in organic synthesis.

noun

1. a yellowish poisonous water-soluble crystalline substance with a penetrating odour, used as a reagent and catalyst in organic synthesis. Formula: OsO 4