misdemeanor, in law, a minor crime, in contrast to a felony. At common law a misdemeanor was a crime other than treason or a felony. Although it might be a grave offense, it did not affect the feudal bond or take away the offender's property. By the 19th cent. serious crimes were labeled felonies, and minor crimes misdemeanors. In the United States a misdemeanor usually is an offense that may be punished summarily by fine and by imprisonment for less than a year. Commission of a misdemeanor does not cancel citizenship or subject an alien to deportation. In some states of the United States certain minor law violations are not even classified as misdemeanors, e.g., traffic offenses and breach of municipal regulations.