Green’s Dictionary of Slang

1. a rogue specializing in short-changing.

1753		J. Poulter Discoveries (1774) 30: The Turners and Pinchers; that is, those getting Change for Money, and keeping some.
1781		G. Parker View of Society II 79: The fingers of a Breslaw or a Jonas are not more dexterous nor quick in the operations of their slight-of-hand profession than the Pinchers are in theirs.
1788, 1796		Grose Classical Dict. of the Vulgar Tongue (2nd, 3rd edn) n.p.: Pinchers. Rogues who, in changing money, by dexterity of hand frequently secrete two or three shillings out of the change of a guinea. This species of roguery is called the pinch, or pinching lay.
1811		Lex. Balatronicum [as cit. 1788].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1859		Matsell Vocabulum 67: pinchers Sometimes called ‘Exchangers;’ fellows who go into stores or exchange offices with a twenty-dollar gold coin and ask to have it changed for bank bills, and after having received the bills, suddenly pretend to have changed their minds, and, handing the bills back again, make very profuse apologies for the trouble they have given, etc., etc.
1862		E. de la Bédollière Londres et les Anglais 316/2: pinchers, voleurs qui opèrent en marchandant des étoffes ou des bijoux. Quelquefois le pincher, après avoir fait un achat, jette négligemment une livre sterling sur le comptoir. On lui rend sa monnaie; il substitue prestement de faux shillings à plusieurs de ceux qui lui sont remis [etc.].
1877		S. James Vagabond Papers (3rd series) 136: You have to go into general business. You must be a magsman, a pincher, a picker-up, a flatcatcher, a bester.

2. a shoplifter, a thief; orig. of those stealing items displayed by a jeweller.

1833		[T. Wontner] Old Bailey Experience 374: [P]inchers. Men of good exterior appearance [...] visit shops, and under the pretence of becoming a customer, convey from the cards of jewellery handed them for inspection, as many valvuables as they can.
1863		Criminal Life (NY) 19 Dec. n.p.: Emeline Langdon, the brazen-faced pincher.
1916		B.E.F. Times 1 Dec. (2006) 130/2: Suspicion has fastened on William, jun., the Potsdam pincher.
1936		‘George Orwell’ Keep The Aspidistra Flying (1962) 19: Book-pinchers, by the look of them.
1961		‘Frank Richards’ Billy Bunter at Butlins 135: Caught you at it, did I, you sneaking pincher?