Green’s Dictionary of Slang

nipping jig n.

[SE nip, to pinch + jig, a dance]
(US)

1. a gallows.

[US]H. Tufts Autobiog. (1930) 292: Nipping jig signifies a gallows.

2. a hanging.

[UK]Farmer & Henley Sl. and Its Analogues V 51/1: Nipping-jig, subs. (old). — Hanging.