Green’s Dictionary of Slang

(UK Und.) dumb.

1648		Dekker ‘Canters Dict.’ Eng. Villainies (9th edn).
1665		Head Eng. Rogue I 48: Canke, Dumb.
1674		Head Canting Academy (2nd edn).
1688		J. Shirley Triumph of Wit.
c.1698		B.E. Dict. Canting Crew.
1714		A. Smith Lives of Most Noted Highway-men, etc. I 209: He taught his Pupil a deal of canting Words, telling him [...] Canke, Dumb.
1719		A. Smith Lives of Most Notorious Highway-men, etc. (1926) 203: Cank, dumb. The cull’s cank, i.e., the rogue’s dumb.
1725		New Canting Dict. n.p.: cank Dumb. The Cull’s Cank; the Rogue’s Dumb; a Term used by Canters, when one of their Fraternity, being apprehended, upon Examination, confesses nothing.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. 1725].
c.1750–1882		B.M. Carew Life and Adventures.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1835		G. Kent Modern Flash Dict.
1848		Flash Dict. in Sinks of London Laid Open.
1859		Matsell Vocabulum.
1881		Trumble Sl. Dict. (1890).