To alter or adjust, particularly in ways not originally intended.
You'll have to jigger it from the original specifications to get it to work.
To use a jigger.
To move, send, or drive with a jerk; to jerk; also, to drive or send over with a jerk, as a golf ball.
To imprison.
To confound; to damn.
Very tired.
Broken.
Damned, in the sense of "I'll be damned if...", expressing utter certainty.