orcein

noun Chemistry.

1. a red dye, the principal coloring matter of cudbear and orchil, obtained by oxidizing an ammoniacal solution of orcinol.

noun

1. 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: C 28 H 24 O 7 N 2

n.

1. A natural dye derived from orcinol and used in various histologic staining methods as a purple dye complex.