Source : Webster's Revised Unabridged Dictionary (1913)

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.