a. Of or pertaining to hell; like hell; infernal; malignant; wicked; detestable; diabolical. “Hellish hate.” Milton. -- Hell"ish*ly, adv. -- Hell"ish*ness, n. [ 1913 Webster ]
(adj) extremely evil or cruel; expressive of cruelty or befitting hell, Syn. unholy, satanic, infernal, hellish, diabolic, diabolical, fiendish, Example: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