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• Murphy's Law
  Murphy's Law

  noun

  the facetious proposition that if something can go wrong, it will.
• Murphy's law
  Murphy's law

  noun

  another term for Sod's law

Murphy's Law

American  

noun

1. the facetious proposition that if something can go wrong, it will.

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Murphy's law British  

noun

1. informal another term for Sod's law

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Murphy's Law Cultural  

1. A rule that states, “If something can go wrong, it will.” An addition to this law reads, “and usually at the worst time.” The identity of “Murphy” is unknown, but the saying was first used during the 1940s and may have originated with members of the armed forces in World War II.

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Murphy's law Idioms  

1. If anything can go wrong, it will, as in We may think we've covered all the details for the benefit, but remember Murphy's law. The identity of Murphy, if ever a real person, is unknown. Some think it alludes to (but was not invented by) a feckless Irishman named Murphy. [c. 1940]

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Etymology

Origin of Murphy's Law

An Americanism dating to 1950–55; named after Edward A. Murphy, Jr., (1918–90), an American aerospace engineer who worked on safety systems

Example Sentences

See Examples For:

Murphy's Law Murphy's law

Byrne stars as Linda, a woman looking Murphy’s Law dead in the eye and screaming in its face.

From Salon ● Feb. 6, 2025

Since the show concluded, Musso has voiced a character in another Disney series, Milo Murphy's Law, and appeared in films Sins of our Youth and The Sand.

From BBC ● Aug. 28, 2023

For example, this might seem like a good time to save a few bucks by getting rid of your renter’s policy, but Murphy’s Law is just waiting to kick you when you’re down.

From Los Angeles Times ● Jul. 6, 2023

Against the backdrop of tight supplies and surging demand came a series of events that struck Pafford as Murphy’s Law in action: Anything that could go wrong did.

From Seattle Times ● Sep. 29, 2021

And of course, Murphy’s Law, the year my mom started buying my clothes too big was the year that I stopped growing.

From "Born a Crime: Stories from a South African Childhood" by Trevor Noah

Call it Murphy’s law, the idea that anything that can go wrong will go wrong.

From Los Angeles Times ● Jul. 23, 2026

The county agreed to a $20 million settlement with Green’s family, which also was represented by Murphy’s law firm.

From Seattle Times ● Nov. 27, 2023

The early-season excitement surrounding the Nets and their glittering roster faded through a season’s worth of head-butting against the Murphy’s law adage that anything that can go wrong usually will.

From New York Times ● Apr. 26, 2022

Murphy’s law for the digital age: anything that can go wrong, will go wrong during a live demonstration.

From Nature ● Nov. 4, 2019

In other words, it is a form of Murphy’s law: things always tend to go wrong!

From "A Brief History of Time: And Other Essays" by Stephen Hawking