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English definition of “fiendish”

fiendish

adjective     /ˈfiːndɪʃ/
EVIL evil or cruel: a fiendish attackViolent or aggressiveUnkind, cruel and unfeelingTreating people or animals badly
DIFFICULT very difficult or complicated: a fiendish crosswordDifficult things and peoplePreventing and impeding
fiendishly adverb mainly UK extremely: fiendishly clever/difficult Very and extremeComplete and wholeIntensifying expressions
(Definition of fiendish adjective from the Cambridge Learner's Dictionary © Cambridge University Press)

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