In politics and government, lapsed power is a term often used to describe a certain constitutionally-granted power of government that is no longer used, according to constitutional convention

Constitutional convention (political custom)

A constitutional convention is an informal and uncodified procedural agreement that is followed by the institutions of a state. In some states, notably those Commonwealth of Nations states that follow the Westminster system and whose political systems derive from British constitutional law, most...

. This may be because the power's original conditions of use no longer exist, making it an anachronism

Anachronism

An anachronism—from the Greek ανά and χρόνος — is an inconsistency in some chronological arrangement, especially a chronological misplacing of persons, events, objects, or customs in regard to each other...

, or simply because the nation's political culture and attitudes have shifted, making the power appear too morally or ethically objectionable to use. However, the power still exists.

Examples of lapsed powers include the reserve powers of a monarch under a constitutional monarchy

Constitutional monarchy

Constitutional monarchy is a form of government in which a monarch acts as head of state within the parameters of a constitution, whether it be a written, uncodified or blended constitution...

. Constitutional monarchs have significant powers over matters such as the appointment of the prime minister

Prime minister

A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime...

 or the veto

Veto

A veto, Latin for "I forbid", is the power of an officer of the state to unilaterally stop an official action, especially enactment of a piece of legislation...

 of legislation, in practice these powers are rarely actually used independently.

Another example of a lapsed power could be the ability of the Pope

Pope

The Pope is the Bishop of Rome, a position that makes him the leader of the worldwide Catholic Church . In the Catholic Church, the Pope is regarded as the successor of Saint Peter, the Apostle...

 to resign his office. Though authorized by the Canon Law

Canon law

Canon law is the body of laws & regulations made or adopted by ecclesiastical authority, for the government of the Christian organization and its members. It is the internal ecclesiastical law governing the Catholic Church , the Eastern and Oriental Orthodox churches, and the Anglican Communion of...

s of the Vatican hierarchy, no Pope has actually done so for centuries. Thus, the power can be considered de facto

De facto

De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...

lapsed.