From Longman Dictionary of Contemporary Englishimpishimp‧ish /ˈɪmpɪʃ/ adjective BAD BEHAVIOUR OR ACTIONSshowing a lack of respect or seriousness in a way that is amusing rather than bad SYN mischievous a little girl with dark hair and an impish grin —impishly adverb
Examples from the Corpus
impish• Afterwards, he settled down and relaxed and became a little bit more impish.• Flat-chested, narrow-hipped, her fair hair sleek from swimming, she looked like an impish boy.• The impish Forrester scribbles pedagogic remarks all over Jamal's unformed jottings and a sparky, mutually nurturing relationship gets going.• He wrote tales of plausible galactic empires with impish fun and a fierce belief that scientific knowledge would triumph over ignorance.• an impish grin• He was a man with a very impish wit. 