Source : Webster's Revised Unabridged Dictionary (1913)

Polyphotal \Pol`y*pho"tal\, Polyphote \Pol"y*phote\, a. [Poly- +
   Gr. ?, ?, light.] (Elec.)
   Pertaining to or designating arc lamps so constructed that
   more than one can be used on a single circuit.