The Acronym stands for a girl that Cant Understand Normal Thinking
Cunt: whyy!?! i dont understand!?! tell meee why!?!
Guy: Goddammit bitch why Cant you Understand Normal Thinking ... oh thats right cause your a CUNT!
It has almost replaced the word 'mate', often used in Australia to refer to people in a conversation when they can't be bothered trying to remember your name.
American feminist: I find that insulting
Sick Aussie Cunt: Piss off
Sick Aussie Cunt 1: Sup cunt?
Sick Aussie Cunt 2: Nothing much, cunt.