† endeˈmoniasmObs.rare—1. [f.Gr. ἐν in + δαίµων, δαίµον-ος demon1, on analogy of enthusiasm.] Inspiration by a demon. 1751Byrom Enthus.Poet.Wks. 1773 II. 24 The variety of delusion with which a different spirit may then possess its votaries will centre..in endemoniasm.