Source : Webster's Revised Unabridged Dictionary (1913)

Multiphase \Mul"ti*phase\, a. [Multi- + phase.]
   Having many phases; specif. (Elec.), pertaining to, or
   designating, a generator producing, or any system conveying
   or utilizing, two or more waves of pressure, or electromotive
   force, not in phase with each other; polyphase.

Source : WordNet®

multiphase
     adj : of an electrical system that uses or generates two or more
           alternating voltages of the same frequency but
           differing in phase angle [syn: {polyphase}]