Rage (Photo credit: raold smeets)

Rack off : push off! get lost! get out of here! also “rack off hairy legs!”.
Rage : party
Rage on : to continue partying – “we raged on until 3am”
Rapt : pleased, delighted
Ratbag : mild insult
Raw prawn, to come the : to bullshit, to be generally disagreeable
Reckon! : you bet! Absolutely!
Reffo : refugee
Rego : vehicle registration
Rellie or relo : family relative
Ridgy-didge : original, genuine
Right, she : it’ll be all right
Right, that’d be : Accepting bad news as inevitable. (“I went fishing but caught nothing.” “Yeah, that’d be right.”)
Rip snorter : great, fantastic – “it was a rip snorter of a party”
Ripper : great, fantastic – “it was a ripper party”
Ripper, you little! : Exclamation of delight or as a reaction to good news
Road train : big truck with many trailers
Roadie : a beer you buy to take away with you
Rock up : to turn up, to arrive – “we rocked up at their house at 8pm”
Rollie : a cigarette that you roll yourself
Roo : kangaroo
Roo bar : stout bar fixed to the front of a vehicle to protect it against hitting kangaroos (also bull bar)
Root (verb and noun) : synonym for f*ck in nearly all its senses: “I feel rooted”; “this washing machine is rooted”; “(s)he’s a good root”. A very useful word in fairly polite company.
Root rat : somebody who is constantly looking for sex.
Ropeable : very angry
Rort (verb or noun) : Cheating, fiddling, defrauding (expenses, the system etc.). Usually used of politicians
Rotten : drunk – “I went out last night and got rotten”
Rubbish (verb) : to criticize