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. [ 1913 Webster ]

2. (Bot.) A lichen (Lecanora tartarea), from which the powder is obtained. [ 1913 Webster ]