Definition of: chromogen

(krō′mə·jen) noun
1. Chem. a Any organic coloring matter or substance capable of yielding a dye. b Any dye derived from naphthalene which develops a brown color on wool by oxidation.
2. Biol. Any substance in an animal or plant which under certain conditions becomes colored or deepens its hue.
—chro′mo·gen′ic adjective