The term 'Grounded Birds of Australia' refers to the two species of large flightless birds native to Australia, the Emu and the Cassowary. The Emu (4 letters) is the largest bird in Australia and the second-largest in the world after the Ostrich. It is a fast-running, powerful bird with long legs and a long neck, and can reach speeds of up to 50 km/h. The Emu is an important part of Aboriginal culture and is featured on the Australian Coat of Arms.