ratite

A member of a diverse group of mostly large, running, flightless birds that lack keels on their sternums, mostly extinct such as the elephant bird and the moa, but including the extant cassowaries, emu, kiwi, ostrich, and rhea; formerly grouped together in the order Struthioniformes, and including the Paleognathae except the tinamous.

Pertaining to running, flightless birds with no keels on their sternums (as opposed to carinate).