Mischievous is a word that refers to someone or something that is inclined to cause harm or play tricks. There are several synonyms used to describe someone who might be mischievous. One term commonly employed to describe the same behavior is "naughty." It can be used to describe someone engaging in mischief as a result of mischief. Another synonym is "impish," which suggests someone innocent but still engaged in planning a prank or mischief.
Another synonym of "mischievous" is "rascally." It will depend on a person's perceived level of mischievousness and how they act towards others. Other usable synonyms include prankish, roguish, trickster, and playful. Each word carries a slightly different connotation, but all of them describe someone who is given to a degree of mischief-making. It is always wise to choose the right word to describe the level of mischievousness accurately.