Definition of "Rhea" :

noun: larger of two tall fast-running flightless birds similar to ostriches but three-toed; found from Brazil to Patagonia

noun: smaller of two tall fast-running flightless birds similar to ostriches but three-toed; found from Peru to Strait of Magellan

noun: fertility goddess in ancient Greek mythology; wife of Cronus and mother of Zeus; identified with Roman Ops and Cybele of ancient Asia Minor