Wiktionary
methimazole
n. (context medicine English) A thioamide drug, ''1-methyl-3H-imidazole-2-thione'', used to treat hyperthyroidism
Wikipedia
Methimazole
Methimazole (also known as Tapazole or Thiamazole or MMI) is an antithyroid drug, and part of the thioamide group. Like its counterpart propylthiouracil, a major side effect of treatment is agranulocytosis.