Green’s Dictionary of Slang

1. a strong drink, usu. the last of an evening.

1808		G. Woodley ‘The Siller Gun’ in Church Yard 89: The Minstrels screw their merriest pin, / The Magistrates wi’ loyal din, / Tak aff their cau’kers .
1825		A Comical Hist. of the King and the Cobbler 34: I’ve baith whisky and porter wi’ me. Haw, man, there’s a cauker to keep your heart warm.
1836		M. Scott Cruise of the Midge I 164: We returned to the cabin [...] having finished off with a caulker of good cognac.
1849		C. Kingsley Alton Locke (1850) 189: Take a caulker? Summat heavy, then?
1851		‘How Sally Hooter Got Snake-Bit’ in T.A. Burke Polly Peablossom’s Wedding 74: ‘That’s the best red eye I’ve swallered in er coon’s age,’ said the speaker, after bolting a caulker.
1863		T. Taylor Ticket-Of-Leave Man Act IV: Now a caulker to clinch the bargain.
1873		in Sl. Dict. 112: Caulker a dram. The term ‘caulker’ is usually applied to a stiff glass of grog ? preferably brandy ? finishing the potations of the evening.
1873		Dundee Courier 14 Jan. 7/3: ‘There’s the postie. I gi’ed him a cauker this mornin’ [...] he has many a cauld blast tae face i’ the winter mornin’s.
1888		‘Rolf Boldrewood’ Robbery Under Arms (1922) 160: When a man’s cold and tired, and [...] down on hs luck as well, a good caulker of grog don’t do him no harm.
1895		Crowe Aus. Sl. Dict. 16: Caulker, a stiff brandy winding up the evening’s potations.

2. a lie.

1850		Bell’s Life in Sydney 23 Feb. 3/1: Blake slipped a ‘caulker’ into Ross and ‘did’ him.
1864, 1867, 1870		Hotten Sl. Dict. 96: Caulker a too marvellous story, a lie. choker has the same sense.
1884		W.C. Russell Jack’s Courtship II 295: I also took care that she should never afterwards be able to charge me with having told her a real caulker.

3. a superlative, first-rate individual.

c.1865

‘She He Barman of Southwark’ in C. Hindley Curiosities of Street Lit. (1871) 141: If you had seen her take them in her hand, / You’d have said she was a caulker.

4. an exceptionally amusing story, which ‘cannot be topped’.

1864, 1867, 1870

Hotten Sl. Dict.