Cudbear \Cud"bear`\ (k?d"b?r`), n. [Also {cudbeard}, corrupted fr. the name of Dr. Cuthbert Gordon, a Scotchman, who first brought it into notice.] 1. A powder of a violet red color, difficult to moisten with water, used for making violet or purple dye. It is prepared from certain species of lichen, especially {Lecanora tartarea}. --Ure. 2. (Bot.) A lichen ({Lecanora tartarea}), from which the powder is obtained.