[ mur-der ]
/ ˈmɜr dər /
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Law. the killing of another human being under conditions specifically covered in law. In the U.S., special statutory definitions include murder committed with malice aforethought, characterized by deliberation or premeditation or occurring during the commission of another serious crime, as robbery or arson (first-degree murder, ormurder one ), and murder by intent but without deliberation or premeditation (second-degree murder, ormurder two ).
Slang. something extremely difficult or perilous: That final exam was murder!
a group or flock of crows.
verb (used with object)
verb (used without object)
to commit murder.
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Idioms about murder

Origin of murder

First recorded in 1300–50; Middle English mo(u)rdre, murder, variant (influenced by Old French murdre, from Germanic ) of murthre; see murther

synonym study for murder

4. See kill1.


self-murder, nounself-murdered, adjective


1. homicide, manslaughter, murder 2. execute, kill1, murder (see synonym study at kill1)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What’s the difference between murder and manslaughter?

Murder is the legal term for the intentional killing of someone or the killing of someone as the result of a complete disregard for their life. Manslaughter is the legal term for the act of killing someone without intending to, often in an accidental way.

There are many specific conditions and interpretations surrounding what constitutes murder and manslaughter, and laws vary by location. The word murder is also commonly used in more general ways. In legal contexts, though, it’s typically used in a way that implies that the killing was intentional or the result of a complete disregard for the victim’s life, and this is the crucial difference between the words.

In the U.S., manslaughter can be classified as voluntary or involuntary. Voluntary manslaughter often involves a person who kills someone through voluntary actions but without intending to harm them. For example, this could apply to a person who unintentionally kills someone during a fight after having been provoked to fight (especially when their actions are considered to go beyond those deemed appropriate for self-defense). Acts labeled as involuntary manslaughter are often reckless but accidental. For example, the term may be applied to a case in which a driver kills someone as a result of their reckless driving (this is sometimes specifically called vehicular manslaughter).

On the other hand, a person who intentionally runs someone over with their car would likely be charged with murder (unless it involved self-defense). Many jurisdictions classify murders with different degrees. For example, if a person intentionally runs someone over with their car after having planned to do it (that is, after having premeditated it), the act would be called first-degree murder. However, if the killing was intentional but not premeditated, it would be called second-degree murder. Of course, the official charge is typically based on what can be proven during a trial.

Here’s an example of murder and manslaughter used correctly in the same sentence.

Example: The accused was originally charged with manslaughter because it appeared to be a reckless driving accident, but the charge was changed to first-degree murder when the police discovered journals in which the driver had written plans to kill the victim and make it look like an accident.

Want to learn more? Read the full breakdown of the difference between murder and manslaughter.

Quiz yourself on murder vs. manslaughter!

Should murder or manslaughter be used in the following sentence?

There is clear evidence that the defendant intended to kill the victim, and therefore the charge must be _____.

How to use murder in a sentence

British Dictionary definitions for murder

/ (ˈmɜːdə) /

verb (mainly tr)
Also (archaic or dialect): murther

Derived forms of murder

murderer, nounmurderess, fem n

Word Origin for murder

Old English morthor; related to Old English morth, Old Norse morth, Latin mors death; compare French meurtre
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with murder


The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.