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English definition of “fiendish”

fiendish

adjective     /ˈfiːn.dɪʃ/
evil and cruel: a fiendish attackUnkind, cruel and unfeelingViolent or aggressiveTreating people or animals badlyInsults and abuse clever and difficult, sometimes in a bad way: a fiendish crossword a fiendish plotComplicated and difficult to doDifficult to understand UK old-fashioned very great: a fiendish price I'm in a fiendish hurry.Serious and unpleasantNot attractive to look atInformal words for bad fiendishness     /-nəs/ noun [U] Unkind, cruel and unfeelingViolent or aggressiveTreating people or animals badlyInsults and abuse
(Definition of fiendish adjective from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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