I'm thirsty = I'm dry as a dead dingo's donger, I'm drier than a nun's nasty
Ozzie burger = burger with bacon, ham, fried eggs, and beetroot (yak)
Barbie = barbeque
Heaps = loads
Roo = kangaroo
Freshie = fresh water crocodile
Salty = salt water crocodile
Stubby = bottle of beer
Sheila = a woman
Bloke = a man
Garbo = garbage man
VB= Victoria Bitter (a beer)
Esky = koelbox
Swag = sort of sleeping bag with built in matrass
Chocker = chock a block = very full
POM = English person (prisoner of the motherland, another explanation is that it's an abbreviation of pomegranate)