The Collaborative International Dictionary of English v.0.48:
Diabolism \Di*ab"o*lism\, n. 1. Character, action, or principles appropriate to the devil. [1913 Webster] 2. Possession by the devil. --Bp. Warburton. [1913 Webster]WordNet (r) 3.0 (2006):
diabolism n 1: a belief in and reverence for devils (especially Satan) [syn: diabolism, demonism, Satanism]