ETYM Old Eng. meschef bad result, Old Fren. meschief; pref. mes- (Latin minus less) + chief end, head, French chef chief. Related to Minus, and Chief.
Reckless or malicious behavior that causes discomfort or annoyance in others; SYN. mischief-making, mischievousness, deviltry, devilry, devilment, rascality, roguery, roguishness, shenanigan.