The Collaborative International Dictionary of English v.0.48:

moa \mo"a\ (m[=o]"[.a]), n. [Native name.] (Zool.)
   Any one of several very large extinct species of wingless
   birds belonging to Dinornis, and other related genera, of
   the suborder Dinornithes, found in New Zealand. They are
   allied to the apteryx and the ostrich. They were probably
   exterminated by the natives before New Zealand was discovered
   by Europeans. Some species were much larger than the ostrich.
   [1913 Webster]

WordNet (r) 3.0 (2006):

moa
    n 1: extinct flightless bird of New Zealand