From Longman Dictionary of Contemporary Englishfiendishfiend‧ish /ˈfiːndɪʃ/ adjective 1 CRUELcruel and unpleasant a particularly fiendish practical joke2 INTELLIGENTvery clever in an unpleasant way a fiendish plan3 DIFFICULTUNPLEASANTextremely difficult or complicated several fiendish exam questions —fiendishly adverb —fiendishness noun [uncountable]
Examples from the Corpus
fiendish• The fiendish complexity of claiming the credits may be putting people off.• a plot of fiendish complexity• Will Robin solve the fiendish crimes?• The whole thing was so oblique, so fiendish in its circumlocutions, that he did not want to accept it.• You want us to endorse some fiendish invention that will be the means of taking human life!• It was somehow medieval and hushed, in the shadow of the pit and its fiendish machinery.• Napalm is among the most fiendish of chemical weapons.• The enemy, supposing we were disabled, set up a fiendish yell of triumph. 