1(n.) a naughty boy; a bad kid; (appellation) 'naughty boy'noun
2'bad boy', usually used as a form of address by parents to call one's son (especially when scolding them); 'little rascal', a form of address for someone who annoys you too much; (adjective) to be of not such good character, usually to describe when someone does something which is not so good (morally) or when someone acts in a way that they shouldn't (this can be considered as a toned down version to the adjective '衰格')