- a dye, about litmus, this is certainly extracted from the lichen Rocella tinctoria; used as a microscopic stain so when a food colouring
- A reddish brown amorphous dyestuff, C7H7NO3, obtained from orcin, and creating the essential coloring matter of cudbear and archil. It's closely associated with litmus.
- A nitrogenous element (C7H7NO3) formed from orcine and ammonia.
Definition for "orcein"
- a dye, about litmus, this is certainly extracted…
Synonym for "orcein"