killer

1 of 2

noun

kill·​er ˈki-lər How to pronounce killer (audio)
1
: one that kills
2
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

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
Some investigators argued for a lone killer, while others suggested a network of individuals acting under occult motivations. Isadora Wandermurem, Time, 22 Oct. 2025 The film sees detectives discover the remains of 23 women and six men at the residence of filmmaker and serial killer Mark Chapel, who is arrested along with a collaborator, Donovan Summers, who is also later detained. Jesse Whittock, Deadline, 22 Oct. 2025 There were no flies on the dead people and animals—even insects had succumbed to the invisible stealth killer. Literary Hub, 22 Oct. 2025 The Monster of Florence is a name coined by Mario Spezi, a former crime reporter for Italy's La Nazione, for a serial killer that terrorized the countryside outside Florence, Italy, between 1968 and 1985. Randall Colburn, Entertainment Weekly, 22 Oct. 2025 See All Example Sentences for killer

Word History

First Known Use

Noun

15th century, in the meaning defined at sense 1

Adjective

1951, in the meaning defined at sense 1

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

Browse Nearby Words

Cite this Entry

“Killer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/killer. Accessed 26 Oct. 2025.

Kids Definition

killer

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

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

More from Merriam-Webster on killer

Last Updated: - Updated example sentences
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