Ra*ti"tae (?), n. pl. [NL., fr. L. ratis a raft; cf. L. ratitus marked with the figure of a raft.] Zool.
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.
© Webster 1913.