murderer

American  

[mur-der-er] / ˈmɜr dər ər /

noun

1. a person who commits murder.

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idioms

1. murderers' row,

   1. the row of cells in a prison where murderers and other violent or hard-core criminals are held.

   2. Baseball. a succession of heavy hitters scheduled to bat one after the other.

   3. any group of notorious or important people.

      a murderers' row of talent;

      a murderers' row of philosophers.

Other Word Forms

• self-murderer noun

Etymology

Origin of murderer

1300–50; Middle English mortherer, mord ( e ) rer; murder, -er ¹

Explanation

If you’re looking for a roommate and someone writes murderer under “occupation,” you should definitely keep looking. A murderer is a person who kills deliberately and without justification. In some instances, killing a person is considered a just or valid action — in a war, a soldier who kills another soldier is not considered to be a murderer, and people who kill in self-defense, to save themselves, are also not murderers. Killing out of anger or for money or revenge is murder, and anyone who does it is a murderer. Charles Manson is in jail for being a murderer. The Old English root of murderer is morðor, "unlawful killing."

Example Sentences

The book does advance one theory of who the murderer is.

From Los Angeles Times • Jan. 26, 2026

"I am not a saint but I am not a murderer either," Kocner said in 2020 in a statement in court.

From Barron's • Jan. 26, 2026

While many see Yamagami as a cold-blooded murderer, some sympathise with his troubled upbringing.

From BBC • Jan. 20, 2026

When the lord chief justice of England is killed on Temple grounds, Gabriel is enlisted to identify the murderer.

From The Wall Street Journal • Dec. 12, 2025

There was a long story about how Marshall had saved the Professor from being unjustly accused and described the murderer so that the police were able to catch him.

From "The Egypt Game" by Zilpha Keatley Snyder

Related Words

• assassin
• executioner