thionine

Etymology
Of origin. See.

Noun

 * 1)  An artificial red or violet dyestuff consisting of a complex sulfur derivative of certain aromatic diamines.
 * 2)  The unsaturated nine-membered heterocycle having eight carbon atoms, one sulfur atom and four double bonds.
 * 1)  The unsaturated nine-membered heterocycle having eight carbon atoms, one sulfur atom and four double bonds.