Mark Gwynn at Ozwords takes “a light-hearted look” at Australian words for the backside; the opening paragraph will explain my post title:
As a kid I was often told by my dad to ‘get off my date’ when he wanted me to get off the lounge and go outside, or to help with some chore. I was surprised to discover many years later, when I started working at the Australian National Dictionary Centre, that date was not a coinage of my dad’s but an established word in Australian English, meaning ‘anus’. Further exposure to Australian English at the ANDC revealed a number of colloquial terms with the same or a similar meaning.
Lots of interesting terms there, like blurter (from blurt ‘to emit breath eruptively’) and bracket (probably from the shape of a pair of round brackets).