n. A harmful or troublesome event, circumstance, or contingency; an action or occurrence attended with evil or vexation; an annoying, frustrating, or hurtful state or condition of things; misfortune; calamity: used with much latitude of application: as, some one is making mischief; the mischief is that he cannot keep his temper.n. The act, state, course, or disposition of causing annoyance, trouble, or harm; vexatious or injurious operation or tendency; the working of damage or disaster: as, the clouds bode mischief; what mischief is he up to now? often used in a kindly or playful sense, or for affectionate excuse: as, the lad is full of mischief, but not vicious.n. One who or that which does harm or causes injury or vexation; a source of trouble or annoyance: as, that child is a mischief.n. Annoyance, injury, or damage caused or produced; harm; hurt: as, to do mischief; irremediable mischief: now never used in the plural.n. The devil. [Colloq.]n. Synonyms Damage, Harm, etc. See injury.To hurt; harm; ruin.To come to harm or misfortune; miscarry.