Green’s Dictionary of Slang

1. (Aus.) a small aluminium boat.

1938		Dly Teleg. (Sydney) 3 Dec. 21/2: But the ‘tinnies’ [i.e abbrev. ‘tin dinghy’] have ‘class’ these days. They still retain their tin skins, but the metal is cut into strips and riveted on like the planks of regular wooden boats. They are built to plans.
1979		Herald (Melbourne) 7 June 35/1: The aluminium ‘tinnie’ has long been a major force in the Australian boat market for its low initial cost, durability and ease of use [AND].
1982		Sun-Herald (Sydney) 5 Sept. 112/1: Tinnies offer value, fun. Dollar for dollar it’s hard to go past the simple aluminium dinghy as a versatile fun boat [AND].
2006		J. Doyce Three Men in a Tinnie [video] Tim’s 3-metre aluminium ‘tinnie’ that has only been sunk once.
2019		C. Hammer Silver [ebook] A tinnie lying low on the sandy mud.
2020		D. Whish-Wilson Shore Leave 197: [T]ugboats, tinnies and cruisers.

2. (orig. Aus. surfing) a can of beer.

1964		B. Humphries A Nice Night’s Entertainment (1981) 79: So we all shacked up there with stacks of the old glühwein, a few crates of tinnies, a couple of little snow bunnies and no complications.
1978		Tharunka (Sydney) 3 Apr. 5/1: The vibes are good, the scoobs are great, the tinnies are cold and the waves aren’t bad either. So for Christ’s sake ya galahs, don’t be mugs, ’ave a go digger.
1985		R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 129: Les placed a dozen tinnies [...] on the floor for Murray to drink.
1999		Guardian Guide 9–15 Oct. 4: We’d just sit down with a couple of tinnies and talk.
1996		P. Temple Bad Debts (2012) [ebook] He gave the can the suck of a man who measures out his days in tinnies.
2003		www.thepantsman.com 🌐 I was intent on just standing at the bar guzzling down VB tinnies.
2012		A. Savage ‘Killing Peacocks’ in Crime Factory: Hard Labour [ebook] Denise handed round tinnies of VB.
2012		J. Fagan Panopticon (2013) 225: Mike cutting your hair with a pie in one hand and a tinny in the other.
2016		Oxford Student 20 May 33/2: As long as the tinnies are cracked out and the chat is freely flowing.
2015		N. Cummins Tales of the Honey Badger [ebook] The kind of confidence usually reserved for a bloke with a gut-full of tinnies at the town dance.
2021		C. Hammer Opal Country 37: He’s sucking on a tinnie.

3. (N.Z. drugs) silver foil, used for wrapping measures of cannabis; thus the measure of cannabis as sold as a single unit.

1995		Dominion (Wellington) 24 Nov. 1: She later suspected that drug deals were taking place at her former home [...] Judge Bouchier said large numbers of people from all over Auckland went to the house between 1990 and 1995 to buy ‘tinnies’ (cannabis bullets) for $20. [Ibid.] 6 Dec. 1: They could buy a ‘tinny’ (cannabis leaf wrapped in tin foil and enough for two or three joints), for about $20.
2008		nz.news.yahoo.com 3 Oct. 🌐 Among the items located at the seven addresses were cannabis tinnies ready for sale.
2012		Truth Newspaper Online (NZ) 29 Mar. 🌐 Some dealers were charging up to $30 for a cannabis tinny.