The term Down Under is a colloquialism which is variously construed to refer either to Australia and New Zealand , or to Australia or New Zealand alone. The term comes from the fact that these countries are in the Southern Hemisphere , 'below' many other countries on the globe.
The persistence of the media use of the term has led to its wide embrace and usage. The Men at Work song "Down Under" became an instantly recognisable, patriotic rallying song. The famous Australian boxing champion Kostya Tszyu was nicknamed "The Thunder from Down Under", as is Australian snooker player Neil Robertson. When the then Miss Australia Jennifer Hawkins was crowned as Miss Universe 2004 in Quito, Ecuador, she was called by the same nickname by host Billy Bush.
According to Roger Ebert's tongue-in-cheek Glossary of Movie Terms, the Down Under Rule "No film set in Australia is allowed to use the word Australia in its title where "Down Under" is an acceptable alternative. For example, we don't get The Rescuers in Australia or Quigley in Australia."