Coloquialism, common in Australia, used as a slang reference to anal sex. It is a play on the slang term for New Zealanders, ie "kiwis" (thus a "kiwi fruit" would be a homosexual). The term is used frequently to refer in a literal sense to unwanted anal sex, in fact having the actual meaning of some untoward event or reprisal being invoked on the target of the speaker.
"Oi, mate. That may pass for manners in Buttfuck Iraq, but if you harrass that lady any further I'm gonna take this can of Fosters and give you a kiwi enema with it."
A kiwi muncher is a very prominent member of either the gay community or the League of Legends community. Kiwi munchers are those who reply to messages and memes with a kiwi emoji to send the message: "I'm looking for a big black sugar daddy to split me like a lumberjack 🥝"
A girl whom hangs around bars with predominantly kiwi-males. Typically getting really drunk on cheap cider's or snakebites. As soon as the alcohol kicks in her mind is set on one thing: kiwi-cock. Looks or size are not important as long as they are "Kiwi" they will fit the criteria.
Girlfriend #1. Ugh what is Sarah seeing in that guy?
Girlfriend #2. Well he is a Kiwi.
Girlfriend #1. Oh yeah I forgot she is a massive Kiwi Whore