Green’s Dictionary of Slang

1. a cheat, a trickster.

1761

Nancy Dawson’s Jests 27: Thus all mankind are jiggers grown, / To work each other’s fall.

2. (Aus.) a truant from school.

1991

P. Corris Aftershock 91: My saviour was one of those truants, jiggers they call them now—aged about ten.