Green’s Dictionary of Slang

1. wealthy, rich.

1871

Punch 14 Oct. 160/2: There’s heaps of tinny fellows who’ll be awful glad to give .

2. (Aus./N.Z.) lucky .

1918		Chronicle NZEF 7 June 205: Remarks are heard on the ‘tinny’ luck or otherwise of the [poker-]players, while the ‘stiffs’ bemoan their luck [DNZE].
1919		W.H. Downing Digger Dialects 50: tinny — Lucky.
1920		W.H. Downing To Last Ridge 47: McAlister had tinny luck. Got a piece on the leg and went off in a stretcher as happy as Larry.
1933		(con. WWI) A.E. Strong in Partridge Sl. Today and Yesterday 287: When I said ‘Hooray’ he called me back and gave me a few francs; I reckon I was very tinny.
1944		J.F. Dettman Here was Glory 25: P’raps yer’d like ter ’ear th’ story uv ’is sudden reformation From a cheap ‘AckWillie’ artist an’ a tinny ‘Two-up’ king [AND].
1959		G. Slatter Gun in My Hand 229: Some people are tinny and always win.
1960		F. Keinzly Tangahano 150: I won two houseys. Ten quid [...] Tinny, eh?
1978		J. Henderson Soldier Country 126: Flukes? Destiny? Fate? Or just: How Tinny Can You Be?
1982		H. Beaton Outside In I i: You’re a tinny bitch.
1988		McGill Dict. of Kiwi Sl. 113/2: tinny lucky.
1996		E. Perkins Not Her Real Name 92: He’s got away with it, the tinny bastard [DNZE].
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

3. (Aus./N.Z.) mean, grasping.

1984

Partridge DSUE (8th edn) 1237/2: since ca. 1935.