In zoogeography, belonging to a geographical division comprising Australia, New Zealand, Tasmania, Celebes, the Moluccas, Papua New Guinea, and adjacent smaller islands: Since Jack was very interested in Australia, he definitely wanted to go to the Australian region with all the interesting and exciting islands.

1. The linguistic phylum including the languages spoken by Australian aborigines: Jack learned that the classification of Australian comprised of more than 100 different kinds of languages spoken by the native Australians.
2. A native or inhabitant of Australia: At Jane's school there was an Australian who spent one year there as an exchange student.