a brown crystalline material formed by the action of ammonia on orcinol and present in orchil: used as a dye, biological stain, and antiseptic. Formula: C28H24O7N2
Word origin
C19: see orcinol
orcein in American English
(ˈɔrsiɪn)
noun
a brownish-red, crystalline dye, C28H24N2O7, the main coloring matter of orchil, obtained from lichens or by treating orcinol with ammonia, and used as a biological stain, reagent, etc.