Dwale \Dwale\, n. [OE. dwale, dwole, deception, deadly nightshade, AS. dwala, dwola, error, doubt; akin to E. dull. See {Dull}, a.] 1. (Bot.) The deadly nightshade ({Atropa Belladonna}), having stupefying qualities. 2. (Her.) The tincture sable or black when blazoned according to the fantastic system in which plants are substituted for the tinctures. 3. A sleeping potion; an opiate. --Chaucer.