Definition of thiazine in US English:



  • Any of a class of molecules containing a ring of one nitrogen, one sulfur, and four carbon atoms, used in dyes and more recently in sedatives.

    • ‘These novel thiazines have an excellent capacity for protecting technical materials from being infected by micro-organisms.’
    • ‘It appears from this study, comparing oxygen radical yields of these substances with those of the photosensitizing dyes in the classes including the xanthenes, acridines, thiazines, and phenazines, that these dyes may be even more potent producers of these highly toxic radicals.’
    • ‘Toluidine blue is a basic dye of the thiazine series closely related to methylene blue.’


Late 19th century: from thio- + azine.