Green’s Dictionary of Slang

1. an act of vomiting; thus chunderous/chundersome adj., fit to make one vomit.

1953		Baker Aus. Speaks vii 169: Chunder, to vomit [...] also chunder, a noun, vomit.
1969		A. Buzo Rooted III iv: It must have been a particularly chunderous undertaking.
1979		D. Maitland Breaking Out 62: A whacking great almighty piss-up. Followed by a quick chunder or two over the back fence.
1986		R. Beckett Dinkum Aussie Dict. 14: Chunder: A technicolour yawn.
1999		Indep. Rev. 1 Nov. 1: A bag of chips, and sometimes a chunder on the top of the No 17 bus.
2002		Drunk Women Homepage 🌐 Floyd are you responsible for the great mid-chunder photo; action shot baby yeah!!!

2. vomit.

1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 9: The hallway of the timothy where they lobbed smelt of chunder.
2007		Observer 16 Sept. 46: I’m a terrible traveller, get car sick [...] and would never willingly undertake a mission that carries a high likelihood of my wearing a helmet full of stomach chunder.

3. general attrib. use.

1967		J. Hibberd White with Wire Wheels (1973) 155: How are you, chunder-chops?
1967		F.J. Hardy in Great Aus. Lover Stories 64: The Yodeller yodelled into the chunder bucket in full technicolour.
1969		A. Buzo Rooted I iii: Old chunder-guts, eh? He was a character, wasn’t he [...] Remember the time he got sick at Davo’s twenty-first.