- a colorless, crystalline, bitter-tasting, water-soluble solid, CH4N2S, derived from urea by replacement of the oxygen with sulfur: used chiefly in photography, inorganic synthesis, and to accelerate the vulcanization of rubber.
- a white water-soluble crystalline substance with a bitter taste that forms addition compounds with metal ions and is used in photographic fixing, rubber vulcanization, and the manufacture of synthetic resins. Formula: H 2 NCSNH 2
