Green’s Dictionary of Slang

(orig. naut.) collapsed drunk.

1951		E. Lambert Sleeping House Party in DSUE (1984).
1977		G. Melly Rum, Bum and Concertina (1978) 153: Most of the ratings were ‘flakers’ in the lavatory.
1984		(con. WW2) T. Jones Heart of Oak [ebook] We had to be a bit careful with the younger Yankee sailors. They had not the stomachs for rum that we had. A couple of sips could get many of them flat out flakers in no time at al.
1988		McGill Dict. of Kiwi Sl. 45/2: flakers drooping drunk and on the way out.
2003		McGill Reed Dict. of N.Z. Sl. 79: flakers Collapsed from too much alcohol, or simply sleeping over at somebody’s place. ANZ mid C20.