Source : Webster's Revised Unabridged Dictionary (1913)

Struthiones \Stru`thi*o"nes\, n. pl. [NL. See {Struthio}.]
   (Zo["o]l.)
   (a) A division, or order, of birds, including only the
       African ostriches.
   (b) In a wider sense, an extensive group of birds including
       the ostriches, cassowaries, emus, moas, and allied birds
       incapable of flight. In this sense it is equivalent to
       {Ratit[ae]}, or {Drom[ae]ognath[ae]}.

Ratitae \Ra*ti"t[ae]\, n. pl. [NL., fr. L. ratis a raft; cf. L.
   ratitus marked with the figure of a raft.] (Zo["o]l.)
   An order of birds in which the wings are small, rudimentary,
   or absent, and the breastbone is destitute of a keel. The
   ostrich, emu, and apteryx are examples.

Source : WordNet®

Ratitae
     n : used in former classifications to include all ratite bird
         orders [syn: {superorder Ratitae}]