diabolical

of, relating to, or worthy of an evil spirit the police quickly mobilized to track down the diabolical serial killer Synonyms cacodemonic, demoniac (also demoniacal), demonian, demonic (also demonical), devilish, fiendish (or diabolic), Luciferian, satanicRelated Words hellish, infernal; baleful, evil, sinister; malevolent, malicious, malignant; heinous, monstrous; black, immoral, iniquitous, nefarious, vicious, vile, villainous, wicked; barbarous, cruel, ferocious, inhuman, savageNear Antonyms celestial, heavenly; beneficent, benevolent, benign, benignant; godly, holy, sainted, saintly; ethical, good, moral, righteous, virtuousAntonyms angelic (or angelical)