What is australian kiss?

The term "Australian kiss" is generally used as a playful euphemism for a French kiss. It humorously implies that an "Australian kiss" is similar to a French kiss, but "down under," referencing the geographic location of Australia relative to France, as well as being a cheeky innuendo. There isn't any cultural or traditional significance to the term in Australia—it's more of a light-hearted expression used in informal contexts.