any of a group of organic compounds containing a ring system composed of four carbon atoms, a sulphur atom, and a nitrogen atom
thiazine in American English
(ˈθaɪəˌzin; ˈθaɪəzɪn)
noun
any of a group of heterocyclic compounds whose molecules contain one atom of nitrogen, one atom of sulfur, and four atoms of carbon, arranged in a ring