This sad and famous Australian song uses several unusual Australian words, not all of which are still in common use.

Definitions

A swagman is a homeless and unemployed wanderer. Think hobo or migrant worker.

A waltzing matilda is a reference to a walking swagman. A swagman would roll up all his possessions in a wool blanket and tie both ends with a single strand of rope. This would make a rudimentary backpack, and as the swagman walked, the roll would progress from side to side. Hence the term "waltzing matilda".

A billy is a kind of makeshift teapot.

A tucker-bag holds food.

A jumbuck is a sheep.

A coolibah tree is a kind of eucalyptus.

A billabong is a creek.