Green’s Dictionary of Slang

1. (US) a counterfeiter.

1858

Green Mountain Freeman (Montpelier, VT) 4 Feb. 1/1: ‘Ain’t a snagger and a counterfeiter the same?’.

2. (Aus./N.Z.) an itinerant worker or tramp, esp. one who is lazy, or work-shy.

1891		Donegal Indep. 24 July 4/2: As I was tramping through the bish Woodongawards from Melbourne, I met a snagger, just this side of the twelve-mile.
1897		Worker (Brisbane) 4 Sept. 8/4: But stop awhile — have you remarked how many ‘guns’ we meet / Away from sheds in private bars and mashing in the street? / Now, for the sake of simple maids, let's write it here in tar : / ‘Poor 'snaggers’ (50 sheep a day) — that’s what they mostly are!
1899		Boy’s Own Paper 11 Mar. 375: The New Zealand ‘snagger’ is one of the restless atoms of the great and growing army of colonial unemployed, who, of course, ostensibly in search of work, devotes his time and attention to the ‘run’ country, obtaining free board and lodging at every station he passes, and all too often, for the truth of his professions, refusing on some plea or other any offer of employment made to him. [...] I have met the snagger in all his different phases, from the unfortunate, who has genuinely tramped thirty or forty miles ‘having heard of a job,’ to the scrubby-bearded ex-criminal, who finds rurality and seclusion advantageous.
1937		Western Mail (Perth) 10 June 53/2: The cow snaggers with their wives and kids [...[ had asembled.

3. in ext./fig. use, a parasite.

1901

Bulletin (Sydney) 6 July 12/4: The latest grievance of the smart Melbourne girl is that the other cats don’t rush to congratulate her when she becomes engaged. [...] Only old ‘married frumps’ write felicitations, and the ‘snags’ who want to be asked to the wedding.

4. (Aus./N.Z.) a poor person who seeks cheap bargains.

1992		R. Park Fence Around the Cuckoo 118: Other snaggers’ attributes appeared in due course in my own stories, as did the unforgettable odour of people wearing aged garments from secondhand shops.
1998		DNZE 749/3: snag v. Obs 1930s ‘Depression’ use, to search for bargains: often as snagger, one who thus searches; and as snagging, searching for bargains.

5. see snags n. (1)