Source : Webster's Revised Unabridged Dictionary (1913)

Iris \I"ris\, n.; pl. E. {Irises}, L. {Irides}. [L. iris,
   iridis, the goddess, Gr. ?, ?, the rainbow, iris of the eye,
   the plant Iris. Cf. {Orris}.]
   1. (Class. Myth.) The goddess of the rainbow, and
      swift-footed messenger of the gods. --Shak.

   2. The rainbow. --Sir T. Browne.

   3. An appearance resembling the rainbow; a prismatic play of
      colors. --Tennyson.

   4. (Anat.) The contractile membrane perforated by the pupil,
      and forming the colored portion of the eye. See {Eye}.

   5. (Bot.) A genus of plants having showy flowers and bulbous
      or tuberous roots, of which the flower-de-luce
      (fleur-de-lis), orris, and other species of flag are
      examples. See Illust. of {Flower-de-luce}.

   6. (Her.) See {Fleur-de-lis}, 2.