from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of a group of organic bases forming unstable bluish or greenish salts and used in making dyes.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. any of a range of organic bases related to phenazine; they form indigo-coloured salts used in making dyes
from The Century Dictionary and Cyclopedia
- n. A basic coal-tar color of unknown constitution, produced when nitroso-dimethyl-aniline hydrochlorid reacts with toluidine.
ind(igo) + amine.(American Heritage® Dictionary of the English Language, Fourth Edition)