devilish /ˈdɛvəlɪʃ/adjective 4adverb 1forms 2 adjective4 •Resembling a devil. •Roguish or mischievous.[S]he gave me that lovely devilish smile that said: I like liberty, and not necessarily accountability. — 2009 •Evil, wicked.For I abhore to smatter / Of one so deuyllysshe a matter. — 1530 •(informal) Excessive, extreme.A devilish effort yielded a devilish success.I had a devilish time moving the wardrobe downstairs. adverb1 •(informal, old-fashioned) Devilishly; very; exceedingly.It was devilish hot outside today. formsmore devilish · most devilish