A serious crime for which the punishment is prison for more than a year or death, although the threshold varies from state to state. Crimes of less gravity are called misdemeanours.
The Office of the Attorney General for the State of California, in 2007, defined a felony as "a crime which may be punishable by imprisonment in a state prison and/or a fine, or death" and a misdemeanor, "a crime punishable by imprisonment in the county jail for not more than one year, by fine, or both."
In almost all American jurisdictions, serious offenses such as murder, rape or armed robbery are felonies. After that, the distinctions become blurred. Some offenses, such as theft, are hybrid in that if the value stolen is above a certain amount, the offense is a felony.
Regretably, there is no standard qualification of a felony in the United States. Federal legislation has preferred to define a felony in terms of the possible sentence for particular offense. Most states follow this standard but some classify offenses as felonies taking into account the place of incarceration: if it exposes the defendant to a state penitentiary, it is a felony. If it is subject to incarceration in a local jail, the offense is considered to be a misdemeanor.
In many regards, nomenclature notwithstanding, the American felony-misdemeanor distinction is similar to that other common law jurisdictions. For example, Canada has a system which divides crime by severity, referring to them as summary conviction offences and indictable offenses. Canada tends to process summary conviction offenses in provincial courts as opposed to federal courts just as the United States maintains separate court systems for felonies and misdemeanors.
This term "felony" is no longer used in England or other Commonwealth countries but remains a major distinction in the United States.
Historically, in England, the term referred to crimes for which the punishment was the loss of land, life or a limb.