Antipodean: pertaining to the
antipodes - the opposite point on the surface of
planet Earth to your current location. Of the
antipodes.
Antipodean: A person from Down under. In England and particularly in London, antipodean is often used as a group label to refer to persons (usually English speaking and of English heritage) originating from Australia, and thier cohorts from New Zealand and occasionaly also those from South Africa. Australia is pretty close to the antipode of England, hence this Anglocentric usage. However, South Africa is not nearly as far down under as Australia.
The reason is that these people form a semi-cohesive cultural group.
The Australians and New Zealanders are well-nigh indistinguishable to the rest of us. Despite some important cultural differences, the South Africans also have a lot in common with them, and tend to hang out together.
For instance, you might say "beer, rugby, The Church and TNT Magazine are staples of Antipodean culture".