Green’s Dictionary of Slang

1. an act of urination.

1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 18: I’m bustin’ for a nice long snakes!
1967		Kings Cross Whisper (Sydney) xxxvii 7/1: You’ve just had your tenth snake’s hiss.
1985		R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 112: Give me five minutes to have a snake’s and put me strides on.
1999		R.G. Barrett Wind & Monkey (2013) [ebook] ‘How about getting us a glass of water while I have a quick snakes’.
2002		Pete’s Aussie Sl. Home Page 🌐 snake’s hiss, snake’s: a piss, urinate.
2002		R.G. Barrett Mystery Bay Blues 119: I got to have a snakes.
2016		N. Cummins Adventures of the Honey Badger [ebook] ‘What if I drop a Richard the Third, ’cause ya gotta have a snake’s hiss immediately after impact. It’s science’.

2. urine.

1983

R. Aven-Bray Ridgey-Didge Oz Jack Lang 9: The hallway of the timothy where they lobbed smelt of chunder and snakes hiss.