killer

1 of 2

noun

kill·​er ˈki-lər How to pronounce killer (audio)
Synonyms of killernext
1
: one that kills
2
: killer whale
3
a
: one that has a forceful, violent, or striking impact
b
: one that is extremely difficult to deal with

killer

2 of 2

adjective

1
: strikingly impressive or effective
a killer smile
a killer résumé
2
: extremely difficult to deal with
a killer fastball
also : causing death or devastation
a killer tornado

Synonyms of killer

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Noun

Adjective

See All Synonyms & Antonyms in Thesaurus

Examples of killer in a Sentence

Noun Heart disease is the leading killer of both men and women. The chemical is used as a weed killer. Adjective killer viruses that claimed millions of lives a killer exercise program guaranteed to whip you into shape
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
Frank Carter, the infamous killer who lured his child victims to their windows with a Freddy Kreuger-esque nursery rhyme has been behind bars for a quarter century. — Christian Zilko, IndieWire, 28 Aug. 2026 Star Arnold Schwarzenegger was keen to do a sequel, but Cameron was busy with other projects, including Aliens in 1986 (another killer sequel). — ArsTechnica, 28 Aug. 2026 Despite Bret’s passionate insistence that his classmate is a serial killer, Croft tells him Robert is a good kid from a good family and sends him back to class. — Louis Peitzman, Vulture, 27 Aug. 2026 Loosely based on the 1987 movie Black Widow and created by Elizabeth Meriwether, Furious stars Rossum as Alice Black, an FBI agent who is tracking a serial killer (played by Lola Petticrew). — Rick Porter, HollywoodReporter, 27 Aug. 2026 See All Example Sentences for killer

Word History

First Known Use

Noun

15th century, in the meaning defined at sense 1

Adjective

1939, in the meaning defined at sense 2

Time Traveler
The first known use of killer was in the 15th century

Phrases Containing killer

Rhymes for killer

See All Rhymes for killer

Browse Nearby Words

killefer
killer
killer app
See all Nearby Words

Cite this Entry

“Killer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/killer. Accessed 1 Sep. 2026.

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Kids Definition

killer

1 of 2 noun
ˈkil-ər
1
: one that kills
2
: killer whale

killer

2 of 2 adjective
1
: strikingly impressive or effective
a killer smile
2
: extremely difficult
a killer exam
also : causing death or devastation
a killer tornado
Last Updated: - Updated example sentences
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