Diabolic

a.	1.	Pertaining to the devil; resembling, or appropriate, or appropriate to, the devil; befitting hell or satan; devilish; infernal; impious; as, a diabolic or diabolical temper or act; the diabolical expression on his face; fires lit up a diabolic scene.
	2.	showing a wicked cunning or ingenuity; as, the cold calculation and diabolic art of some statesmen.
	3.	extremely evil or cruel; atrocious; outrageously wicked; as, diabolical sorcerers under the influence of devils; diabolical torturers taking pleasure in their craft.

Adj.	1.	diabolic - showing the cunning or ingenuity or wickedness typical of a devil; "devilish schemes"; "the cold calculation and diabolic art of some statesmen"; "the diabolical expression on his face"; "a mephistophelian glint in his eye" Synonyms: devilish, diabolical, mephistophelean, mephistophelian
	2.	diabolic - extremely evil or cruel; expressive of cruelty or befitting hell; "something demonic in him--something that could be cruel"; "fires lit up a diabolic scene"; "diabolical sorcerers under the influence of devils"; "a fiendish despot"; "hellish torture"; "infernal instruments of war"; "satanic cruelty"; "unholy grimaces" Synonyms: demonic, fiendish, satanic, unholy, hellish, infernal, diabolical

Draconian, Mephistophelian, Tartarean, abominable, accursed, animal, anthropophagous, appalling, atrocious, awful, bad, barbaric, barbarous, base, beastly, bestial, bloodthirsty, bloody, bloody-minded, brutal, brutalized, brute, brutish, cannibalistic, corrupt, cruel, cruel-hearted, cursed, damnable, demoniac, demoniacal, demonic, demonish, demonlike, depraved, devil-like, devilish, diabolical, dreadful, evil, execrable, fell, feral, ferocious, fiendish, fiendlike, fierce, flagitious, foul, ghoulish, heinous, hellborn, hellish, hideous, horrible, horrid, ill, impious, infernal, inhuman, inhumane, iniquitous, maleficent, malevolent, malicious, malign, monstrous, murderous, odious, ogreish, ruthless, sadistic, sanguinary, sanguineous, satanic, savage, serpentine, sharkish, sinful, sinister, slavering, subhuman, terrible, truculent, unchristian, uncivilized, ungodly, unhallowed, unhuman, vicious, vile, wicked, wolfish