1. (a.) Resembling, characteristic of, or pertaining to, the devil; diabolical; wicked in the extreme.

2. (a.) Extreme; excessive.

Acherontic Draconian Lethean Mephistophelian Plutonian Plutonic Stygian Tartarean accursed animal anthropophagous arch atrocious bad barbaric barbarous beastly bestial bloodthirsty bloody bloody-minded brutal brutalized brute brutish cannibalistic chthonian chthonic crazy cruel cruel-hearted cursed damnable demoniac demoniacal demonic demonish demonlike devil-like diabolic diabolical elfish elvish evil execrable fell feral ferocious fiendish fiendlike fierce flagitious foolish full of mischief ghoulish heinous hellborn hellish high-spirited impish infernal inhuman inhumane iniquitous knavish madcap maleficent malevolent malign malignant mischief-loving mischievous murderous naughty nefarious ogreish pandemoniac pandemonic playful prankish pranksome pranky puckish purgatorial roguish ruthless sadistic sanguinary sanguineous satanic savage scampish scapegrace serpentine sharkish sinful sinister slavering sportive subhuman sulfurous trickish tricksy truculent unchristian uncivilized ungodly unhallowed unhuman vicious villainous waggish wicked wolfish