1. (a.) Pertaining to hell; diabolical; as, infernal spirits, or conduct\; suitable for hell, or to the character of the inhabitants of hell; hellish.

2. (a.) of or pertaining to or suitable for the lower regions, inhabited, according to the ancients, by the dead; pertaining to Pluto's realm of the dead, the Tartarus of the ancients.

3. (n.) An inhabitant of the infernal regions; also, the place itself.

Acherontic Draconian Hadean Lethean Mephistophelian Plutonian Plutonic Stygian Tartarean absolute animal anthropophagous atrocious barbaric barbarous beastly bestial blamed blasted blessed bloodthirsty bloody bloody-minded brutal brutalized brute brutish cannibalistic chthonian chthonic cimmerian confounded cruel cruel-hearted cursed cussed damnable damned demoniac demoniacal demonic demonical devilish diabolic diabolical dire downright dreadful evil execrable fell feral ferocious fiendish fiendlike fierce flagitious ghoulish heinous hellborn hellish inhuman inhumane iniquitous maleficent malevolent malicious murderous nether out-and-out outright pandemoniac pandemonic plutonian plutonic purgatorial ruthless sadistic sanguinary sanguineous satanic savage sharkish sinister slavering straight-out stygian subhuman sulfurous thoroughgoing truculent unchristian uncivilized underworld ungodly unhuman vicious villainous wicked wolfish