1playful misbehaviour, especially on the part of children:she’ll make sure Danny doesn’t get into mischief
playfulness that is intended to tease or create trouble:her eyes twinkled with irrepressible mischief
2harm or trouble caused by someone or something:she was bent on making mischief
[count noun] archaic a person responsible for harm or annoyance.
3 Law a wrong or hardship that a statute is designed to remove or for which the common law affords a remedy:the statute was passed to prevent a mischief in respect of which the defendant was already under a duty at common law
do someone (or oneself) a mischief
British informal injure someone or oneself:I would have done myself a mischief if I’d carried on