Green’s Dictionary of Slang

1. (Aus.) taking advantage of luck; looking after one’s own interests.

1882		Sydney Sl. Dict. (2 edn) 6: On the Never - To take advantage of, to best.
1890		Bulletin (Sydney) 12 July 12/4: How comes it that Moss Vale township, with the small population of 800 all told, occupies fifth position on the N.S.W. insolvency returns [...]? Can it be through vice-royalty travelling ‘on the never’ when rusticating, or can it arise from the stingy habits of the beau monde of Sydney whose estates are scattered around?
1904		Sun. Times (Perth) 24 Jan. 4/5: Black Goose George has sworn a mighty oath that no ex-MP shall travel on the never over the railway lines.
1910		Bulletin (Sydney) 20 Oct. 13/4: On the Warrego (Q.) I struck a station boss who handed me the gratuitous pannikin of dust in a neat paper bag with: ‘If you please, sir.’ When travelling ‘on the never’ one appreciates little touches like that.
1955		N. Pulliam I Travelled a Lonely Land (1957) 236/2: on the never – making the most of, taking advantage of.

2. (Aus. Und.) working a form of confidence trick.

1885

Bulletin (Sydney) 7 Mar. 13/1: ‘Well, the fact is […] there’s nothin’ to be made ‘on the never’ now; there’s too many on the bloomin’ game. If you cop a mug out of the Metropolitan, and are just a getting him away right, ’bout six of seven in the same line wants to stand in; and that puts the mug fly and chokes him off the push.

3. see on the never-never (system) under never-never, the n.²