"fiendish" in German fiendish mörderisch brutal schwierig arg wüst gemein vertrackt perfid perfide dämonisch diabolisch Detailed translations for "fiendish" fiendish 1. colloquial fiendish(also: grueling, gruelling) mörderisch fiendish brutal schwierig fiendish(also: bad, serious, terrible, terribly) arg fiendish(also: waste) wüst fiendish(also: mean, hateful, miserable, wicked) gemein fiendish vertrackt{adjectiv} 2. other fiendish(also: ghoulish) perfid fiendish(also: ghoulish) perfide fiendish(also: ghoulish) dämonisch fiendish(also: ghoulish) diabolisch{adjectiv} English synonyms for "fiendish" fiendish {s} demonic diabolic diabolical hellish infernal satanic unholy