A misdemeanor, or misdemeanour, in many common law legal systems, is a "lesser" criminal act. Misdemeanors are generally punished less severely than felonies, but theoretically more so than administrative infractions (also known as regulatory offenses). Many misdemeanors are punished with monetary fines. Usually only repeat misdemeanor offenders are punished by actual jail time.
In the United States, the federal government generally considers a crime punishable by a year or less in prison to be a misdemeanor. All other crimes are felonies. Many states also follow this.
The distinction between a felony and misdemeanor has been abolished by most other common law jurisdictions (e.g. Crimes Act 1958 (Vic., Australia) s. 332B(1), Crimes Act 1900 (NSW., Australia) s. 580E(1)). Those jurisdictions have generally adopted some other classification, e.g. in Canada, Australia, the Republic of Ireland and the United Kingdom, the crimes are divided into summary offences and indictable offences.
In some jurisdictions, those who are convicted of a misdemeanor are known as misdemeanants (as contrasted with those convicted of a felony who are known as felons). Depending on the jurisdiction, examples of misdemeanors may include: petty theft, prostitution, public intoxication, simple assault, disorderly conduct, trespass, vandalism, and other similar crimes. In the United States, misdemeanors are crimes with a maximum punishment of 12 months of incarceration, typically in a local jail (again, as contrasted with felons, who are typically incarcerated in a prison). Those people who are convicted of misdemeanors are often punished with probation, community service or part-time imprisonment, served on the weekends.
Misdemeanors usually do not result in the loss of civil rights, but may result in loss of privileges, such as professional licenses, public offices, or public employment. Such effects are known as the collateral consequences of criminal charges. This is more common when the misdemeanor is related to the privilege in question (such as the loss of a taxi driver's license after a conviction for reckless driving), or when the misdemeanor involves moral turpitude and in general is evaluated on a case-by-case basis. One prominent example of this is found in the United States Constitution, which provides that the President may be impeached by Congress for "high crimes and misdemeanors" and removed from office accordingly. The definition of a "high" misdemeanor is left to the judgment of Congress.
Within classes of offenses, the form of punishment can vary widely. For example, the US federal government and many U.S. states divide misdemeanors into several classes, with certain classes punishable by jail time and others carrying only a fine. When a statute does not specify the class, it is referred to as an unclassified misdemeanor. Sometimes this is done when legislators wish to impose a penalty that falls outside the framework specified in the classes. For instance, Virginia has four classes of misdemeanors, with Class 1 and Class 2 misdemeanors being punishable by twelve-month and six-month jail sentences, respectively, and Class 3 and Class 4 misdemeanors being non-jail offenses payable by fines; but first-time marijuana possession is an unclassified misdemeanor punishable by serving up to 30 days in jail.