CLY,
Money. To cly the Jerk, to be Whipt. Let's strike his Cly; Let's get his Money from him. Also a Pocket, as, Filed a Cly, Pick'd a Pocket.
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Entry taken from 1736 Canting Dictionary, by Nathan Bailey.
Cly in the 1811 Vulgar Tongue
Also see examples in Canting Songs and Slang Rhymes collected by John S. Farmer (1896).