The Collaborative International Dictionary
Rhea \Rhe"a\, n. [L., a proper name.] (Zo["o]l.) Any one of three species of large South American ostrichlike birds of the genera Rhea and Pterocnemia. Called also the American ostrich.
Note: The common rhea, or nandou ( Rhea Americana), ranges from Brazil to Patagonia. Darwin's rhea ( Pterocnemia Darwinii), of Patagonia, is smaller, and has the legs feathered below the knee.
Nandou \Nan"dou\, Nandu \Nan"du\, n. [Braz. nhandu or yandu.] (Zo["o]l.) Any one of three species of South American ostriches of the genera Rhea and Pterocnemia, especially the smallest, Pterocnemia pennata (formerly Rhea Americana), called also the common rhea. They are tall fast-running flightless birds similar to ostriches but three-toed, found from Peru to the Straits of Magellan. See Rhea. [Written also nandow.]