Source : Webster's Revised Unabridged Dictionary (1913)

Depolarization \De*po`lar*i*za"tion\, n. [Cf. F.
   d['e]polarisation.]
   The act of depriving of polarity, or the result of such
   action; reduction to an unpolarized condition.

   {Depolarization of light} (Opt.), a change in the plane of
      polarization of rays, especially by a crystalline medium,
      such that the light which had been extinguished by the
      analyzer reappears as if the polarization had been
      anulled. The word is inappropriate, as the ray does not
      return to the unpolarized condition.

Source : WordNet®

depolarization
     n : a loss of polarity or polarization [syn: {depolarisation}]