| Noun | 1. | ratite bird - flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches; cassowaries; emus; moas; rheas; kiwis; elephant birdsbird - warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings Struthio camelus, ostrich - fast-running African flightless bird with two-toed feet; largest living bird cassowary - large black flightless bird of Australia and New Guinea having a horny head crest Dromaius novaehollandiae, Emu novaehollandiae, emu - large Australian flightless bird similar to the ostrich but smaller apteryx, kiwi - nocturnal flightless bird of New Zealand having a long neck and stout legs; only surviving representative of the order Apterygiformes Rhea americana, rhea - larger of two tall fast-running flightless birds similar to ostriches but three-toed; found from Brazil to Patagonia nandu, Pterocnemia pennata, rhea - smaller of two tall fast-running flightless birds similar to ostriches but three-toed; found from Peru to Strait of Magellan aepyornis, elephant bird - huge (to 9 ft.) extinct flightless bird of Madagascar moa - extinct flightless bird of New Zealand |