The Collaborative International Dictionary of English v.0.48:

Arc \Arc\ ([aum]rk), v. i. [imp. & p. p. Arcked ([aum]rkt); p.
   pr. & vb. n. Arcking.] (Elec.)
   To form a voltaic arc, as an electrical current in a broken
   or disconnected circuit.
   [Webster 1913 Suppl.]