imp·ish 
/ˈɪmpɪʃ/ adjective
/ˈɪmpɪʃ/ adjective [more impish; most impish] : having or showing a playful desire to cause trouble : playful and mischievous
▪ an impish grin/smile ▪ an impish face/look
▪ an impish grin/smile ▪ an impish face/look
— imp·ish·ly adverb
▪ grinning impishly
▪ grinning impishly
— imp·ish·ness noun [noncount]
▪ his youthful impishness
▪ his youthful impishness
