fiendishPronunciation: /ˈfiːndɪʃ/Translate fiendish | into German | into Italian | into Spanish Definition of fiendish adjective extremely cruel or unpleasant:fiendish methods of torture informal extremely awkward or complex:a fiendish problemDerivatives fiendishly adverb [as submodifier]:a fiendishly clever plan fiendishness noun fiendish in other Oxford dictionaries Definition of fiendish in the US English dictionary
