2. (Zool.) (a) An American duck (Aythya Americana) highly esteemed as a game bird. It is closely allied to the canvasback, but is smaller and its head brighter red. Called also red-headed duck. American poachard, grayback, and fall duck. See Illust. under Poachard. (b) The red-headed woodpecker. See Woodpecker. [ 1913 Webster ]
3. (Bot.) A kind of milkweed (Asclepias Curassavica) with red flowers. It is used in medicine. [ 1913 Webster ]