Green’s Dictionary of Slang

jim-screechy adj.

also jim-skreechie
[jimscreech v.]

(W.I.) underhand, deceitful.

[WI]M. Montague Dread Culture 188: Jim skreechie – not upfront, sneaky, illegal business.
[WI]Francis-Jackson Official Dancehall Dict. 28: Jim-screechy sneaky, underhand: u. wha’ kin’ a jim-screechy business dat?