Frob -- Short for 'Frobnicate'

According to The Jargon File:
/frob'ni-kayt/ vt. [Poss. derived from frobnitz, and usually abbreviated to 'frob', but `frobnicate' is recognized as the official full form.] To manipulate or adjust, to tweak. One frequently frobs bits or other 2-state devices. Thus: "Please frob the light switch" (that is, flip it), but also "Stop frobbing that clasp; you'll break it". One also sees the construction `to frob a frob'. See tweak and twiddle.