fiendish Definition

diabolical, demonic, wicked, diabolic, evil, infernal, satanic, hellish, unholy, demoniacal, cruel, devilish, devious, dastardly, malevolent, cunning, sinister, monstrous, murderous, ghoulish, maniacal, sadistic, demented, nefarious, ghastly, fearsome, grotesque, bloodthirsty, merciless, hideous, loathsome, macabre, vile, mephistophelean, insidious, ruthless, perfidious, wily, villainous, fiendful, fiendlike, psychopathic, ogreish, remorseless, vampiric, ingenious, beastly, vengeful, deranged, wizardly, bloodcurdling, crazed, zany, megalomaniac, necromantic, creepy, terrifying, damnable, eldritch, homicidal, succubi, reptilian, superhuman, insane, tentacled, guileful, daffy, lovecraftian, psychokinetic, avaricious, knightly, vainglorious, scelestic, undead, vulpine, ratlike, conscienceless, villainousness, clever, batlike, holmesian, wacky, paranoiac, goatish, menacing, monomaniacal, elvish, brutish, pantomimic, sociopathic, maggoty, priapic, doltish, mysterious, inventive, freaky, petrifying, falstaffian, cadaverous, manic,