Flannel  —n. 1 a woven woollen usu. Napless fabric. B (in pl.) Flannel garments, esp. Trousers. 2 face-cloth, esp. Towelling. 3 slang nonsense; flattery. —v. (-ll-; us -l-) 1 slang flatter. 2 wash with a flannel. [welsh gwlanen from gwlan wool]