Green’s Dictionary of Slang

jigger v.3

1. [late 19C–1930s] a euph. for damn v.

2. (also fiddle) as past participle of sense 1, with an additional feeling of confusion.

In exclamations

I’ll be jiggered! (also ...hog-wallered! …jammed! ...jiggerooed! ...jig-swiggered! ...jimjammed! ...jumped up! I’m jiggered!)

[mid-19C+] a general excl. of surprise, irritation.