Green’s Dictionary of Slang

1. (UK Und.) defective or crooked, usu. of weights and measures.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 265: slang weights, or measures: unjust, or defective ones.
1844		New Sprees of London 3: I’ll introduce you to the [...] flash and slang Mots, Donners, and Cullies that's faking the slums on the cross.
1859		Hotten Dict. of Modern Sl. etc. 94: slang counterfeit or short weights and measures. A slang quart is a pint and a half. slang measures are lent out at 2d. per day. The term is used principally by costermongers.
		Bombay Gaz. 1 Nov. 2/3: The ‘Squire’ put him on the shockingly slang ‘Shocking Mamma’ for the Cesarewitch.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 474/2: If we give slang weights, how many rich shop-keepers is fined for that there?

2. nouveaux riche, vulgar, raffish; thus talk slang, to talk in a flashy manner.

1800		G.S. Carey ‘Every Man His Mode’ in One Thousand Eight Hundred 29: The Coachman, tho’ plain, is an absolute fop, / With [...] his broad silver buttons, and tripple-eap’d coat, / And all the slang speeches of Newgate by rote.
1837		Sydney Monitor 18 Jan. 4/1: [A] calanes hat, with a silk hadkerchief [sic] tied under it, in the most slang fashion possible.
1841		Morn. Post 21 Aug. 5/2: With his hands stuck into the loopholes of an old Taglioni, and a particularly slang tile, he conveys a perfect personation of [...] a marker at a third-rate billiard table.
1846		Swell’s Night Guide 74: This is a lush ken in the neighbourhood of Southwark. The Rum Cul – a downey card, is patronised by the leary and slang schools, in winter, his long room, or ‘slanging lumber’ is the scene of many choice spree and downey movements.
1848		Bell’s Life in Sydney 12 Feb. 3/1: snobs! snobs! ye are horrible things / With your slang paletots and your trumpery rings.
1850		Chester Chron. 1 June 4/5: The Etonian of 1850 is not what he was during the twenty years preceding 1845. ‘Slang’ pervades the whole animal, he is slang in his language, slang in his gait, and slang in his costume.
1850		Sydney Morn. Herald 23 Feb. 2/4: Others in the rags of their half-slang gentility, with the velvet collars of their paletots worn through to the canvas.
1856		G.J. Whyte-Melville Kate Coventry (1865) 9: Such smart people [...] the slang aristocracy, as they are called, muster in great force at Ascot. [Ibid.] 120: A slang-looking man with red whiskers meeting under his chin.
1861		John Bull 13 Apr. 235/2: A plain commonplace sort of Englishman [...] generally inclined to be somewhat ‘slang’ in his costume [Ibid.] 235/3: The tastes of that slang class which is apt to affect an exclusive claim to the homage of all who are concerned about the horse.
1863		Story of a Lancashire Thief 11: I’ve heard him talk slang like a professional. Once I heard him telling two chums of his about tooling his drag to the Derby; in fact he knew all about traps, and casks, and drags, and rounders.
1880		Illus. Police News 4 Sept. 4/5: [T]heir only thought is to frequent balls, drink a great deal of champagne, talk very grossly of their partners, drop in at a slang Cellar [and] finish the night with kidneys and porter.