Source : Webster's Revised Unabridged Dictionary (1913)

Nasturtium \Nas*tur"tium\, n. [L. nasturtium, for nasitortium,
   fr. nasus nose + torquere, tortum, to twist, torture, in
   allusion to the causing one to make a wry face by its pungent
   taste. See {Nose} of the face, and {Torture}.]
   1. (Bot.) A genus of cruciferous plants, having white or
      yellowish flowers, including several species of cress.
      They are found chiefly in wet or damp grounds, and have a
      pungent biting taste.

   2. (Bot.) Any plant of the genus {Trop[ae]olum}, geraniaceous
      herbs, having mostly climbing stems, peltate leaves, and
      spurred flowers, and including the common Indian cress
      ({Trop[ae]olum majus}), the canary-bird flower ({T.
      peregrinum}), and about thirty more species, all natives
      of South America. The whole plant has a warm pungent
      flavor, and the fleshy fruits are used as a substitute for
      capers, while the leaves and flowers are sometimes used in
      salads.

Source : WordNet®

nasturtium
     n 1: any tropical American plant of the genus Tropaeolum having
          pungent juice and long-spurred yellow to red flowers
     2: aquatic herbs [syn: {genus Nasturtium}]
     3: flowers and seeds and leaves all used as flavorings