- a white, slightly water-soluble, bitter, crystalline powder C4H4N2OS, used chiefly in treating hyperthyroidism by reducing the activity of the thyroid gland.
- a white crystalline water-insoluble substance with an intensely bitter taste, used in medicine to treat hyperthyroidism; 2-thio-4-oxypyrimidine. Formula: C 4 H 4 N 2 OS
