Source : Webster's Revised Unabridged Dictionary (1913)

Interrupter \In`ter*rupt"er\, n.
   1. One who, or that which, interrupts.

   2. (Elec.) A device for opening and closing an electrical
      circuit; a vibrating spring or tuning fork, arranged to
      make and break a circuit at rapidly recurring intervals,
      by the action of the current itself.

Source : WordNet®

interrupter
     n : a device for automatically interrupting an electric current