Australian English is different from British and American English in that it has a bias towards invention, deception, profanity, humour and a classless society. The story of Australian language, from 1788 to the present day, is actually the story of the Australian nation.
Kel Richards, author of the book, The Story of Australian English, explained, the beginning of Australian accent emerged following the arrival of European settlers in 1788. They all spoke differently and they used different words and what they had to do, in order to communicate with each other, was to level their dialect variations down. English dialect words, patois spoken by thieves called the Flash language, some military terms and Indigenous language have all informed the Australian vocabulary.
It is important to remember that a key feature of Australian colloquialisms are that they are never static and often shift meaning or spelling over time.