The Collaborative International Dictionary of English v.0.48:

Atropine \At"ro*pine\, n. [Gr. ? inflexible; hence ? ?, one of
   the three Parc[ae]; 'a priv. + ? to turn.] (Chem.)
   A poisonous, white, crystallizable alkaloid, extracted from
   the Atropa belladonna, or deadly nightshade, and the
   Datura Stramonium, or thorn apple. It is remarkable for its
   power in dilating the pupil of the eye. Called also
   daturine.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Atropa \Atropa\ n.
   a genus of plants of the nightshade family, including the
   belladonna (Atropa belladonna).

   Syn: genus Atropa.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

Death's-herb \Death's"-herb`\, n.
   The deadly nightshade (Atropa belladonna). --Dr. Prior.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Belladonna \Bel`la*don"na\, n. [It., literally fine lady; bella
   beautiful + donna lady.] (Bot.)
   (a) An herbaceous European plant (Atropa belladonna) with
       reddish bell-shaped flowers and shining black berries.
       The whole plant and its fruit are very poisonous, and the
       root and leaves are used as powerful medicinal agents.
       Its properties are largely due to the alkaloid atropine
       which it contains. Called also deadly nightshade.
   (b) A species of Amaryllis (Amaryllis belladonna); the
       belladonna lily.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. (Her.) The tincture sable or black when blazoned according
      to the fantastic system in which plants are substituted
      for the tinctures.
      [1913 Webster]

   3. A sleeping potion; an opiate. --Chaucer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Atropa belladonna
    n 1: perennial Eurasian herb with reddish bell-shaped flowers
         and shining black berries; extensively grown in United
         States; roots and leaves yield atropine [syn: belladonna,
         belladonna plant, deadly nightshade, Atropa
         belladonna]