Green’s Dictionary of Slang

(Aus./US) liquor, a drink; thus as v. gurgle, to have a drink.

1890		Dead Bird (Sydney) 22 Mar. 2/1: ‘Early Bird’ and the Prodigal Son were doing their usual gin crawl down George-street [...] After unearthing the necessary coppers they gurgled.
1895		Truth (Sydney) 17 Feb. 3/4: Yes, the times is werry ’ard, / An we carn’t make grub an’ gurgle.
1904		Sydney Sportsman (Surry Hills, NSW) 12 Oct. 1/2: ‘Bring me a corpse reviver, quick,’ yelled the Sydneyite, and he swallowed the gurgle.
1942		Berrey & Van den Bark Amer. Thes. Sl.
1966–9		in DARE.