different between poltergeistism vs poltergeistic

English

Etymology

poltergeist +? -ism

Noun

poltergeistism (uncountable)

1. The supposed manifestation of the presence of one or more poltergeists, especially as involving physical objects which move or fly about without warning.
   • 1920, E. H. Jones, The Road to En-Dor, John Lane (London), p. 28:

     "Breakin' windows and such," Hall said; "reg'lar Mafficking night they 'ad last night. Put the wind up them all proper."

     "Poltergeistism!" I ejaculated.

   • 1958, Robert Wallace, "House of Flying Objects," Life, 17 March, p. 55:

     There are numerous records of poltergeists in the scientific and quasi-scientific literature of Europe and the U.S., although there is probably no case of poltergeistism anywhere that has been authenticated beyond reasonable doubt.

   • 2002, Mulaika Hijjas, "Family Ghosts," Feminist Studies, vol. 28, no. 2, p. 372:

     Robert Foong had noted that the tactics of aggrieved family ghosts were more along the lines of passive-aggressive than poltergeistism. Nevertheless, Juliet gave a covert look around the room for handy missiles.

English

Etymology

poltergeist +? -ic

Adjective

poltergeistic (comparative more poltergeistic, superlative most poltergeistic)

1. Of, pertaining to, or resembling a poltergeist, poltergeists, or poltergeistism.
   • 1953, Anthony Flew, A New Approach to Psychical Research, p. 28:

     To avoid commitment to any theory it might be better, though awkward, to speak of poltergeistic disturbances or poltergeistic outbreaks. These are sporadic, starting suddenly and unexpectedly and ending just as suddenly.

   • 1963, W. F. Jackson Knight, Folklore, vol. 74, no. 1, p. 302:

     In the same disused church there had also been ‘poltergeistic’ phenomena. It was discovered that they were due to the presence of ‘elemental’, sub-human, spirits.

   • 2006, Brad Steiger, Revelation: The Divine Fire, ?ISBN, p. 195:

     But then the apartment began to be visited by poltergeistic manifestations. They would awaken in the morning to find bookcases turned over, furniture strewn about, the entire living room in a mess.

References

• Oxford English Dictionary, 2nd ed., 1989.