What does "emu" mean?

Emu: A large Australian bird, of two species (Dromaius Novæ- Hollandiæ and D. irroratus), related to the cassowary and the ostrich. The emu runs swiftly, but is unable to fly. [Written also emeu and emew.] Note: The name is sometimes erroneously applied, by the Brazilians, to the rhea, or South American ostrich. Emu wren. See in the Vocabulary.