| Noun | 1. | nandu - smaller of two tall fast-running flightless birds similar to ostriches but three-toed; found from Peru to Strait of Magellanflightless bird, ratite, ratite bird - flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches; cassowaries; emus; moas; rheas; kiwis; elephant birds | |