A person who worships or believes in demons; = demonist.
Origin
Early 18th century; earliest use found in Daniel Defoe (?1660–1731), writer and businessman. Probably an alteration of demonist after agent nouns ending in -ast, e.g. enthusiast.
Definition of demoniast in US English:
demoniast
noundɪˈməʊnɪast
rare
A person who worships or believes in demons; = demonist.
Origin
Early 18th century; earliest use found in Daniel Defoe (?1660–1731), writer and businessman. Probably an alteration of demonist after agent nouns ending in -ast, e.g. enthusiast.