Australasian

Australasian is an adjective relating to Australasia, a geographic region in the southern Pacific Ocean that roughly includes Australia, New Zealand, and nearby islands. The term is widely used in geography and biogeography, and is sometimes encountered in cultural or marketing contexts. In geographic usage there is no single universal boundary; definitions typically include Australia and New Zealand, with varying inclusion of New Guinea, eastern Indonesian islands, and numerous Pacific island groups.

In biogeography, Australasian refers to the Australasian realm, one of the Earth's major biogeographic realms. This realm covers Australia, New Guinea, and many Pacific islands, and is distinguished by its distinctive flora and fauna that developed in long geographic isolation from other regions. The boundary with the neighboring Indomalayan realm is often described by the Wallace Line, a historic biogeographic boundary that marks differences in species composition.

Etymology and usage: the term derives from Austral- plus -an, built on the name Australasia, which in turn draws from Latin australis meaning southern. The adjective Australasian is commonly used to describe things associated with the region or its institutions, as well as to refer to people in a broad regional sense. For individuals, more precise demonyms such as Australian or New Zealander are typically used, but Australasian can appear in discussions of regional collaboration, events, or markets that span Australia, New Zealand, and nearby Pacific areas.

In summary, Australasian denotes both a geographic-cultural region and a biogeographic realm, with definitions and emphasis varying by context.