roadrunnerPronunciation: /ˈrəʊdrʌnə/Definition of roadrunner noun a slender fast-running bird of the cuckoo family, found chiefly in arid country from the southern US to Central America. Genus Geococcyx, family Cuculidae: two species, in particular the (greater) roadrunner (G. californianus) roadrunner in other Oxford dictionaries Definition of roadrunner in the US English dictionary