Synonyms of 'fiendish'

animal, atrocious, bad, baleful, barbaric, barbarous, beastly, bestial, bloodthirsty, bloody, brutal, Brute, brutish, cruel, cursed, damnable, demoniac, demoniacal, demonic, devilish, diabolic, Draconian, evil, execrable, fell, feral, ferocious, fierce, heinous, hellish, infernal, inhuman, inhumane, maleficent, malevolent, malicious, malign, malignant, monstrous, murderous, outrageous, ruthless, sadistic, sanguinary, sanguineous, satanic, savage, serpentine, sinister, subhuman, Tartarean, truculent, unchristian, uncivilized, ungodly, unhallowed, vicious, wicked, wolfish