Demoniac

a.	1.	Pertaining to, or characteristic of, a demon or evil spirit; devilish; as, a demoniac being; demoniacal practices. Sarcastic, demoniacal laughter. - Thackeray.
	2.	Influenced or produced by a demon or evil spirit; as, demoniac or demoniacal power.
	3.	resembling or suggesting possession by a demon; as, demoniac energy.
	4.	in a murderous frenzy as if possessed by a demon.
n.	1.	A human being possessed by a demon or evil spirit; one whose faculties are directly controlled by a demon. The demoniac in the gospel was sometimes cast into the fire. - Bates.
	2.	(Eccl. Hist.) One of a sect of Anabaptists who maintain that the demons or devils will finally be saved.

Noun	1.	demoniac - someone who acts as if possessed by a demon
Adj.	1.	demoniac - in a murderous frenzy as if possessed by a demon; "the soldier was completely amuck"; "berserk with grief"; "a berserk worker smashing windows" Synonyms: amok, amuck, berserk, demoniacal, possessed
	2.	demoniac - resembling or suggesting possession by a demon; "demoniac energy"; "a demoniacal fit" Synonyms: demoniacal

aliene, bedlamite, borderline case, crackbrain, crackpot, crazed, crazy, dement, demonic, devilish, diabolic, energumen, fanatic, fired, flake, fou, idiot, insane, inspired, kook, loon, loony, lunatic, madman, maniac, meshuggenah, noncompos, nut, phrenetic, raving lunatic, satanic, screwball, serpentine, unhallowed, weirdo