kill·​er | \ ˈki-lər How to pronounce killer (audio) \

Definition of killer

 (Entry 1 of 2)

1 : one that kills
3a : one that has a forceful, violent, or striking impact
b : one that is extremely difficult to deal with



Definition of killer (Entry 2 of 2)

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

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Synonyms & Antonyms for killer

Synonyms: Noun

Synonyms: Adjective

Antonyms: Adjective

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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
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Recent Examples on the Web: Noun An east side Detroit man accused of being a killer in the mid '90s was exonerated Thursday, clearing him of the false charges and opening the door to wrongful conviction lawsuits against the state and city. Frank Witsil, Detroit Free Press, "Detroit man imprisoned for murders he didn't commit is freed, 26 years too late," 17 Dec. 2020 Not playing Saturday because of Michigan’s cancellation is a killer for the former Georgia backup. Michael Casagrande |, al, "Heisman Trophy race is dead heat with DeVonta Smith closing," 9 Dec. 2020 Deshaun Watson has played well lately, but losing receiver Will Fuller is a killer. Los Angeles Times, "NFL week 13 picks: Titans edge Browns; Rams beat Cardinals; Chargers lose," 4 Dec. 2020 Any injuries during the fantasy playoffs can be killer. Steve Gardner, USA TODAY, "Fantasy football waiver wire: Shore up playoff roster with Texans' Keke Coutee," 2 Dec. 2020 The woman now maintains that Smith wasn’t the killer, his lawyers say. Matt Sledge,, "Secret payments, DNA evidence and split jury undermine New Orleans murder conviction, lawyers say," 26 Nov. 2020 The brand is also insanely cool, and the formulas are killer. Bella Cacciatore, Glamour, "Fenty Beauty Black Friday Sale 2020: Best Makeup Deals to Shop," 24 Nov. 2020 For now, there isn't a killer must-have MagSafe feature. Dan Patterson, CBS News, "Getting started with MagSafe, the iPhone 12's best new feature," 20 Nov. 2020 Controlling the ball is so important in the weather the last two games, as mentioned, and for the Texans to control the ball and come away empty twice -- the series mentioned at the top and this one -- is killer. Dan Labbe, cleveland, "Browns rediscovered their identity on Sunday’s most important drive: Rewatch observations," 17 Nov. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'killer.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of killer


15th century, in the meaning defined at sense 1


1951, in the meaning defined at sense 1

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Time Traveler for killer

Time Traveler

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

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Statistics for killer

Last Updated

13 Jan 2021

Cite this Entry

“Killer.” Dictionary, Merriam-Webster, Accessed 25 Jan. 2021.

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More Definitions for killer


How to pronounce killer (audio)

English Language Learners Definition of killer

 (Entry 1 of 2)

: a person or thing that kills someone or something
informal : something that is very difficult



English Language Learners Definition of killer (Entry 2 of 2)

chiefly US
: causing death or destruction
informal : very impressive or appealing
informal : very difficult


kill·​er | \ ˈki-lər How to pronounce killer (audio) \

Kids Definition of killer

 (Entry 1 of 2)

: someone or something that takes the life of a person or animal



Kids Definition of killer (Entry 2 of 2)

1 : very impressive or effective a killer smile
2 : very difficult a killer exam
3 : causing death or ruin a killer tornado

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