Source : Webster's Revised Unabridged Dictionary (1913)

Proselytism \Pros"e*ly*tism\, n. [Cf. F. pros['e]lytisme.]
   1. The act or practice of proselyting; the making of converts
      to a religion or a religious sect, or to any opinion,
      system, or party.

            They were possessed of a spirit of proselytism in
            the most fanatical degree.            --Burke.

   2. Conversion to a religion, system, or party.

Source : WordNet®

proselytism
     n 1: the practice of proselytizing
     2: the state of being a proselyte; spiritual rebirth resulting
        from the zeal of crusading advocacy of the gospel