The Collaborative International Dictionary of English v.0.48:

Okra \O"kra\, n.
   1. (Bot.) An annual plant (Abelmoschus esculentus syn.
      Hibiscus esculentus), whose green pods, abounding in
      nutritious mucilage, are much used for soups, stews, or
      pickles; gumbo. [Written also ocra and ochra.]
      [1913 Webster]

   2. The pods of the plant okra, used as a vegetable; also, a
      dish prepared with them; gumbo.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

Hibiscus esculentus
    n 1: tall coarse annual of Old World tropics widely cultivated
         in southern United States and West Indies for its long
         mucilaginous green pods used as basis for soups and stews;
         sometimes placed in genus Hibiscus [syn: okra, gumbo,
         okra plant, lady's-finger, Abelmoschus esculentus,
         Hibiscus esculentus]