Open English Wordnet
Adjectives
(s)demonic, diabolic, diabolical, fiendish, hellish, infernal, satanic, unholyextremely 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”