1. The belief in demons.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• demontise,
• deminise,
• deemonise,
• demonisee,
• deminism,
• demonsim,
• demmonism,
• demoniism,
• demonismm,
• damonism,
• deoonism,
• desmodiym,
• endemonism,
• demonianism,
• demomnist,
• demonnist,
• demonistt,
• Demonmst,
• demonimy,
• demoinomy

• demonic,
• denounce,
• demonize,
• demonise,
• demming,
• demoniac,
• denning,
• demoniacal.

The adjective form of the word "demonism" is "demonic".

The plural of the "demonism" can be the "demonisms".

The singular of the "demonism" can be the "demonism".