Demoniac

[dɪ'məʊnɪæk] or [dɪ'monɪ,æk]

(noun.) someone who acts as if possessed by a demon.

Checked by Bernie--From WordNet

(a.) Alt. of Demoniacal

(n.) A human being possessed by a demon or evil spirit; one whose faculties are directly controlled by a demon.

(n.) One of a sect of Anabaptists who maintain that the demons or devils will finally be saved.

Checked by Juliana

n. Person possessed by a demon, or evil spirit.

a. Diabolical, devilish, infernal.

Edited by Kelsey

They writhed her regal face to a demoniac mask. Charlotte Bronte. Villette.
This was a demoniac laugh--low, suppressed, and deep--uttered, as it seemed, at the very keyhole of my chamber door. Charlotte Bronte. Jane Eyre.

Checker: Nona