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 But Dees insisted Mieske needed exhortations from the White Aryan Resistance to take the leap from vicious fantasist to actual killer. oregonlive, "White supremacists on trial for inciting murder required extraordinary security in Portland; case reverberates 30 years later," 8 Jan. 2020 And while the lineup includes some killer names, this year's round-up of headliners is another reminder that Coachella and other music festivals still have a problem including women headliners. Allie Gemmill, Teen Vogue, "Coachella 2020 Full Lineup: Travis Scott, BIGBANG, Megan Thee Stallion, and More," 3 Jan. 2020 As the case for her son's killer moves through the court system, Cowherd continues to remember and honor her son each day. Billy Kobin, The Courier-Journal, "'It's like a repeated cycle': Louisville's murder toll climbed 14% in 2019," 3 Jan. 2020 Supreme Leader Ayatollah Ali Khamenei vowed to avenge Soleimani’s killers, according to a statement. Nick Wadhams, Fortune, "Trump-Ordered Airstrike Kills Iranian Commander, Escalating Tensions and Roiling Global Markets," 3 Jan. 2020 The same goes for tricky weather, exciting rapids, and killer fishing conditions. Popular Science, "The 10 best canoe trips in the U.S. and Canada," 1 Jan. 2020 So does that mean that these two deranged killers can live happily ever after with their growing family in the suburbs? Erica Gonzales, Harper's BAZAAR, "People Are Furious with Joe After the Last Scene of the You Season 2 Finale," 28 Dec. 2019 Make no mistake, this killer is not required to serve anywhere near 40 years. Conrad Swanson, The Denver Post, "Convicted murderer, 18, sentenced to life in prison," 27 Dec. 2019 Come for the Emmy award-winning performance by Comer (and the equally perfect Oh), stay for Villanelle’s wild assassination techniques and her wardrobe that’s somehow even more killer. Emily Tannenbaum, Glamour, "So You've Finished You Season 2 and Need Something to Watch ASAP," 27 Dec. 2019

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 2020

Cite this Entry

“Killer.” The Dictionary, Merriam-Webster Inc., Accessed 25 January 2020.

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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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More from Merriam-Webster on killer

Thesaurus: All synonyms and antonyms for killer

Rhyming Dictionary: Words that rhyme with killer

Spanish Central: Translation of killer

Nglish: Translation of killer for Spanish Speakers

Britannica English: Translation of killer for Arabic Speakers

Comments on killer

What made you want to look up killer? Please tell us where you read or heard it (including the quote, if possible).


dull or mediocre

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