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: Webster's Revised Unabridged Dictionary (1913)