Source : Webster's Revised Unabridged Dictionary (1913)

Reactor \Re*act"or\, n. (Elec.)
   A choking coil.

Source : WordNet®

reactor
     n 1: an electrical device used to introduce reactance into a
          circuit
     2: (physics) any of several kinds of apparatus that maintain
        and control a nuclear reaction for the production of
        energy or artificial elements [syn: {nuclear reactor}]