Found 2 items, similar to fiendish.
English → English (WordNet) Definition: fiendish fiendish adj : extremely 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” [syn: demonic, diabolic, diabolical, hellish, infernal, satanic, unholy]
English → English (gcide) Definition: Fiendish Fiendish \Fiend"ish\, a. Like a fiend; diabolically wicked or cruel; infernal; malignant; devilish; hellish. -- Fiend"ish*ly, adv. -- Fiend"ish*ness, n. [1913 Webster]