1. (a.) Pertaining to, or characteristic of, a demon or evil spirit; devilish; as, a demoniac being; demoniacal practices.

2. (a.) Influenced or produced by a demon or evil spirit; as, demoniac or demoniacal power.

Draconian Mephistophelian Tartarean abandoned amok animal anthropophagous atrocious barbaric barbarous beastly bellowing berserk bestial bloodthirsty bloody bloody-minded brutal brutalized brute brutish cannibalistic carried away cruel cruel-hearted cursed damnable delirious demoniac demonic demonish demonlike devil-like devilish diabolic distracted ecstatic enraptured execrable fell feral ferocious fiendish fiendlike fierce frantic frenzied fulminating furious ghoulish haggard hellborn hellish hog-wild howling hysterical in a transport in hysterics infernal inhuman inhumane intoxicated mad madding maniac murderous ogreish orgasmic orgiastic possessed rabid raging ramping ranting raving ravished roaring running mad ruthless sadistic sanguinary sanguineous satanic savage sharkish slavering storming subhuman transported truculent unchristian uncivilized uncontrollable ungodly unhuman vicious violent wild wild-eyed wild-looking wolfish