Synonyms of diabolical

1 Syllable

vile, cruel

2 Syllables

ghoulish, heinous, evil, monstrous, vicious, chthonian, feller, grody, hellborn, ogreish, wicked, hellish, fiendish

3 Syllables

inhuman, villainous, shameful, infernal, teratoid, demoniac, demonic, coldblooded, atrocious, devilish, ferine, satanic, sulphurous, miscreated

4 Syllables

demonical, serpentine, demoniacal, satanical, inhumane

5 Syllables

mephistophelian