Green’s Dictionary of Slang

1. (Aus./N.Z.) a sleep or nap, esp. after a drinking session.

1928		Morwell Advertiser IVic.) 21 Sept. 2/6: The is Albie Hammond’s hut. I came in here for a snore off.
1934		Morwell Advertiser (Vic.) 11 Oct. 5/3: A snore-off. Hill was asleep in the car.
1940		Western Mail (Perth) 30 May 2/3: Combo [...[ well-oiled and feeling like a snore-off, lay down on captain Pinnell’s desk.
1949		R. Park Poor Man’s Orange 9: He’s a hard worker, Lord dear, and it wouldn’t be You who’d send him to everlasting fire for missing mass, when it’s the only chance he’s got of a bit of a snore-off.
1959		(con. 1940s) G. Slatter Gun in My Hand 92: Come on now. Have a snore off [...] Sleep it off, Dig.
1969		B. Crump Warm Beer 179: If you want to borrow Wattie’s grave here for a snore-off till he gets off work, I’m sure he won't mind.
1974		J. Gaby restless Waterfront 171: I chased a couple down ten minutes ago, and there’s three more there now having a snore-off.
2003		McGill Reed Dict. of N.Z. Sl. 194: snore-off A short sleep. ANZ early C20.

2. in attrib. use of sense 1.

1956

Argus (Melbourne) 21 Aug. 3: Oh, that’s the snore-off room. If you happen to be tired, you can [...] lie on a couch.