The Collaborative International Dictionary of English v.0.48:

ostrich \os"trich\ ([o^]s"trich), n. [OE. ostriche, ostrice, OF.
   ostruche, ostruce, F. autruche, L. avis struthio; avis bird +
   struthio ostrich, fr. Gr. ?, fr. ? bird, sparrow. Cf.
   Aviary, Struthious.] [Formerly written also estrich.]
   (Zool.)
   A large bird of the genus Struthio, of which Struthio
   camelus of Africa is the best known species. It has long and
   very strong legs, adapted for rapid running; only two toes; a
   long neck, nearly bare of feathers; and short wings incapable
   of flight. The adult male is about eight feet high.
   [1913 Webster]

   Note: The South African ostrich (Struthio australis) and
         the Asiatic ostrich are considered distinct species by
         some authors. Ostriches are now domesticated in South
         Africa in large numbers for the sake of their plumes.
         The body of the male is covered with elegant black
         plumose feathers, while the wings and tail furnish the
         most valuable white plumes.
         [1913 Webster]

   Ostrich farm, a farm on which ostriches are bred for the
      sake of their feathers, oil, eggs, etc.

   Ostrich farming, the occupation of breeding ostriches for
      the sake of their feathers, etc.

   Ostrich fern (Bot.) a kind of fern (Onoclea
      Struthiopteris), the tall fronds of which grow in a
      circle from the rootstock. It is found in alluvial soil in
      Europe and North America.
      [1913 Webster]

WordNet (r) 3.0 (2006):

ostrich fern
    n 1: tall fern of northern temperate regions having graceful
         arched fronds and sporophylls resembling ostrich plumes
         [syn: ostrich fern, shuttlecock fern, fiddlehead,
         Matteuccia struthiopteris, Pteretis struthiopteris,
         Onoclea struthiopteris]