Noun

law (countable and uncountable; plural laws)

1. (uncountable) The body of rules and standards issued by a government, or to be applied by courts and similar authorities.

   By law, one is not allowed to own a wallaby in New York City.

2. A particular such rule.

   A new law forbids driving on that road.

3. (more generally) A written or understood rule that concerns behaviours and the appropriate consequences thereof. Laws are usually associated with mores.

   "Do unto others as you wish them to do unto you" is a good law to follow.

4. A one-sided contract.
5. A well-established, observed physical characteristic or behavior of nature.

   Newton and Einstein understood the law of gravitation in very different ways.

6. (mathematics) A statement that is true under specified conditions.
7. A category of English "common law" petitions that request monetary relief, as opposed to relief in forms other than a monetary judgment; compare to "equity".
8. (cricket) One of the official rules of cricket as codified by the MCC.
9. (slang, uncountable) The police.

   Here comes the law — run!

Synonyms

• (observed physical law): theorem
• (in mathematics): theorem

Derived terms

• above the law
• against the law
• a law unto oneself
• Ampère’s law
• Avogadro’s law
• Beer-Lambert law
• Boyle’s law
• bylaw
• canon law
• Charles’ law
• civil law
• common law
• contract law
• corn laws
• Coulomb’s law
• criminal law
• de Morgan’s laws
• dumb law
• employment law
• family law
• Faraday’s laws
• federal law
• feudal law
• Fourier’s law
• Gauss’s law
• Graham’s law
• Gresham’s law
• Henry’s law
• Hooke’s law
• Hubble’s law
• international law
• into law
• Kepler’s laws of planetary motion
• Kerchoff’s laws
• law and order

• lawgiver
• lawlike
• law lord
• lawmaker, law-maker
• law of cosines
• law of large numbers
• law of sines
• law of small numbers
• law of tangents
• law of the tongue
• lay down the law
• long arm of the law
• lynch law
• martial law
• Moore’s law
• Murphy's law
• natural law
• Newton’s law of cooling
• Newton’s law of gravitation
• Newton’s laws of motion
• Ohm’s law
• physical law
• power law
• Poiseuille’s law
• possession is nine points of the law
• property law
• Roman law
• statuate (statute)+law=statuate law (US)
• state law
• statute law (Commonwealth English)
• Stefan-Boltzmann law
• Stokes’ law
• sus law
• take the law into one’s own hands
• three laws of robotics
• unwritten law
• Zipf’s law

Law is a system of rules, usually enforced through a set of institutions. Laws can shape or reflect politics, economics and society in numerous ways and serves as a primary social mediator of relations between people.

Contract law regulates everything from buying a bus ticket to trading on derivatives markets. Property law defines rights and obligations related to the transfer and title of personal (often referred to as chattel) and real property. Trust law applies to assets held for investment and financial security, while tort law allows claims for compensation if a person's rights or property are harmed.

If the harm is criminalised in a statute, criminal law offers means by which the state can prosecute the perpetrator. Constitutional law provides a framework for the creation of law, the protection of human rights and the election of political representatives. Administrative law is used to review the decisions of government agencies, while international law governs affairs between sovereign nation states in activities ranging from trade to environmental regulation or military action. Writing in 350 BC, the Greek philosopher Aristotle declared, "The rule of law is better than the rule of any individual."

Legal systems elaborate rights and responsibilities in a variety of ways. A general distinction can be made between civil law jurisdictions, which codify their laws, and common law systems, where judge made law is not consolidated. In some countries, religion informs the law. Law provides a rich source of scholarly inquiry, into legal history, philosophy, economic analysis or sociology. Law also raises important and complex issues concerning equality, fairness and justice. "In its majestic equality", said the author Anatole France in 1894, "the law forbids rich and poor alike to sleep under bridges, beg in the streets and steal loaves of bread."

In a typical democracy, the central institutions for interpreting and creating law are the three main branches of government, namely an impartial judiciary, a democratic legislature, and an accountable executive. To implement and enforce the law and provide services to the public, a government's bureaucracy, the military and police are vital. While all these organs of the state are creatures created and bound by law, an independent legal profession and a vibrant civil society inform and support their progress.