"A pale yellow crystalline glycoside obtained from quercitron bark, which yields quercetin and rhamnose on hydrolysis and is used as a dye", Mid 19th cent.; earliest use found in Encyclopaedia Britannica. From French quercitrin, quercitrine from quercitr- (in quercitron) + -in.[quercitrin etymology, quercitrin origin, 英语词源]