Green’s Dictionary of Slang

jigger v.2

[jigger n.1 ]

1. to lock up, to imprison.

[UK]H. Caine Deemster Ch. xxxiii: Poor Mastha Dan had been [...] jiggered up in Peel Castle.
[US]H. Leverage ‘Dict. Und.’ in Flynn’s mag. cited in Partridge DU (1949).

2. to unlock.

[US]Sutton & Linn Where The Money Was (2004) 210: He was going to jigger the door in a way that would allow us to get in.