a stain or colouring matter; a compound consisting of chromophore and auxochrome groups attached to one or more benzene rings, its colour being due to the chromophore and its dyeing affinities to the auxochrome. Dyes are used for intravital colouration of living cells, staining tissues and microorganisms, as antiseptics and germicides, and some as stimulants of epithelial growth. For individual dyes, see the specific names. Commonly but improperly used for radiographic contrast medium.
Origin: a.S. Deah, deag