Source : Webster's Revised Unabridged Dictionary (1913)

Spiritualism \Spir"it*u*al*ism\, n.
   1. The quality or state of being spiritual.

   2. (Physiol.) The doctrine, in opposition to the
      materialists, that all which exists is spirit, or soul --
      that what is called the external world is either a
      succession of notions impressed on the mind by the Deity,
      as maintained by Berkeley, or else the mere educt of the
      mind itself, as taught by Fichte.

   3. A belief that departed spirits hold intercourse with
      mortals by means of physical phenomena, as by rappng, or
      during abnormal mental states, as in trances, or the like,
      commonly manifested through a person of special
      susceptibility, called a medium; spiritism; the doctrines
      and practices of spiritualists.

            What is called spiritualism should, I think, be
            called a mental species of materialism. --R. H.
                                                  Hutton.

Source : WordNet®

spiritualism
     n 1: (theology) any doctrine that asserts the separate existence
          of God
     2: the belief that the spirits of dead people can communicate
        with people who are still alive (especially via a medium)
     3: concern with things of the spirit [syn: {spirituality}, {otherworldliness}]