Source : Webster's Revised Unabridged Dictionary (1913)

Pluralism \Plu"ral*ism\, n.
   1. The quality or state of being plural, or in the plural
      number.

   2. (Eccl.) The state of a pluralist; the holding of more than
      one ecclesiastical living at a time. [Eng.]

Source : WordNet®

pluralism
     n : the doctrine that reality consists of several basic
         substances or elements