from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of a class of aromatic compounds found widely in plants, especially the yellow crystalline form, C6H4O2, used in making dyes, tanning hides, and photography.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. any of a class of aromatic compounds having two carbonyl functional groups in the same six-membered ring
from the GNU version of the Collaborative International Dictionary of English
- n. A crystalline substance, C6H4O2 (called also benzoketone), first obtained by the oxidation of quinic acid and regarded as a double ketone; also, by extension, any one of the series of which quinone proper is the type.
from The Century Dictionary and Cyclopedia
- n. The general name applied to all benzene derivatives in which two hydrogen atoms are replaced by two oxygen atoms.
- n. Specifically, a compound obtained by distilling kinic acid with diluted sulphuric acid and peroxid of manganese, or by the oxidation of aniline with chromic acid.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any of a class of aromatic yellow compounds including several that are biologically important as coenzymes or acceptors or vitamins; used in making dyes
quinine + -one (Wiktionary)