noun

• A country and island in Oceania. Official name: Commonwealth of Australia. Capital: Canberra.
• 1814, Matthew Flinders, A Voyage to Terra Australis, volume 1 (at Project Gutenberg)
• (geology) A continent consisting of the islands of Australia, New Guinea and intervening islands. New Guinea and the intervening islands are also on the Australian tectonic plate and are thus geologically considered part of the continent.