Source : Webster's Revised Unabridged Dictionary (1913)

Thionine \Thi"on*ine\, n. [Gr. ? brimstone, sulphur.] (Chem.)
   An artificial red or violet dyestuff consisting of a complex
   sulphur derivative of certain aromatic diamines, and obtained
   as a dark crystalline powder; -- called also {phenylene
   violet}.