jerry, n.⁷ — Green’s Dictionary of Slang

jerry n.⁷

1. a look, a glance; a means of identification, a grasp of understanding of the situation.

1943

Baker ‘Influence of American Sl. on Australia’ in AS XVIII:4 256: I’m a quick jerry they ain’t john hops.

2. (Aus.) one who posesses ‘inside’ information.

1920		Northam Courier (WA) 24 Sept. 2/2: If I only was a jerry to the secret of the sting, / I’d buy a racehorse for myself, and call him Golden Stope.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 13: But his brother surgeons [...] swore blind that they were not a jerry to any of his alleged moonlit adventures on the roads leading in and out of London and he was acquitted.

take a jerry (v.)

to change one’s behaviour or course of action (for the better).

1919		W.H. Downing Digger Dialects 30: jerry — to understand suddenly. ‘Take a jerry’ — change (for the better) one’s course of conduct.
1924		(con. WWI) A.G. Pretty Gloss. Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: jerry. [...] To ‘take a jerry’ – change (for the better) ones [sic] course of conduct.

take a jerry to (v.) (also have a jerry to)

(Aus./N.Z.) to investigate and understand something, to work something out.

1906		Sun. Times (Perth) 1 July 4/8: Please tell J.C. W. we’ve a ‘jerry’ to his joke.
1909		Star (Sydney) 8 July 13/3: ‘Den dey all take a jerry dat dey are mugs’.
1938		X. Herbert Capricornia (1939) 210: Use y’ bit o’ brains [...] an’ take a jerry to y’ self.
1963		L.F. Freed Crime in S. Afr. 105: When he says he ‘rooks the weed’ he means that he smokes dagga, and when he says that he is ‘bang the ore will take a jerry’, he intends to imply that he is afraid the police may find out.