Source : Webster's Revised Unabridged Dictionary (1913)

Bustard \Bus"tard\ (b[u^]s"t[~e]rd), n. [OF. & Prov. F.
   bistarde, F. outarde, from L. avis tarda, lit., slow bird.
   --Plin. 10, 22; ``proxim[ae] iis sunt, quas Hispania aves
   tardas appellat, Gr[ae]cia 'wti`das.''] (Zo["o]l.)
   A bird of the genus {Otis}.

   Note: The great or {bearded bustard} ({Otis tarda}) is the
         largest game bird in Europe. It inhabits the temperate
         regions of Europe and Asia, and was formerly common in
         Great Britain. The {little bustard} ({O. tetrax})
         inhabits eastern Europe and Morocco. Many other species
         are known in Asia and Africa.

Source : WordNet®

bustard
     n : large heavy-bodied chiefly terrestrial game bird capable of
         powerful swift flight; classified with wading birds but
         frequents grassy steppes