A broker or factor, as a coal crimp, who disposes of the cargoes of the Newcastle coal ships; also persons employed to trapan or kidnap recruits for the East Indian and African companies. To crimp, or play crimp; to play foul or booty: also a cruel manner of cutting up fish alive, practised by the London fishmongers, in order to make it eat firm; cod, and other crimped fish, being a favourite dish among voluptuaries and epicures.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
See also the definition in Nathan Bailey's 1736 dictionary of canting and thieving slang.
Crim * Crinkum CrankumNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes