1 killer | Definition of killer

killer

noun
kill·​er | \ ˈki-lÉ™r 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

killer

adjective

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

Keep scrolling for more

Synonyms & Antonyms for killer

Synonyms: Noun

bear, beast, chore, headache, job, labor

Synonyms: Adjective

baleful, deadly, deathly, fatal, fell, lethal, mortal, murderous, pestilent, terminal, vital

Antonyms: Adjective

healthful, healthy, nonfatal, nonlethal, wholesome

Visit the Thesaurus for More 

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
See More

Recent Examples on the Web: Noun

Harold Shipman was one of the most prolific serial killers in history. Hannah Fry, The New Yorker, "What Statistics Can and Can’t Tell Us About Ourselves," 2 Sep. 2019 Heart disease is far and away the number one killer in this country (some 1 in 4 deaths are associated with it). Sy Mukherjee, Fortune, "The Diseases That Are Increasingly Killing Americans: Brainstorm Health," 27 Aug. 2019 And in Mindhunter season 2, actor Oliver Cooper (of Project X and Californication fame) made for a seriously convincing fictional version of the killer. Heather Finn, Good Housekeeping, "What the Real 'Mindhunter' Season 2 Serial Killers Look Like Compared to the Actors," 24 Aug. 2019 Tuberculosis is the single leading infectious killer in the world, infecting an estimated 10 million people in 2017 and killing 1.6 million of them. Beth Mole, Ars Technica, "How a new antibiotic destroys extremely drug-resistant tuberculosis," 16 Aug. 2019 Viewers were obsessed with the hunky profiler who wasn't afraid to chase down the most dangerous serial killers in the country. Megan Stein, Country Living, "Here's the Real Reason Shemar Moore Left 'Criminal Minds'," 10 Aug. 2019 The men’s final featured Dora against Australia’s Liam O’Brien, who became a giant killer in the event. Joe Haakenson, Daily Pilot, "Sage Erickson wins U.S. Open of Surfing women’s title, denying rival Courtney Conlogue repeat," 4 Aug. 2019 For example, Stoneman Douglas reported no trespassing in 2017-18, even though the brother of the killer was arrested for trespassing a few weeks after the shooting. Scott Travis, sun-sentinel.com, "South Florida school districts ‘most problematic’ in complying with safety laws," 25 July 2019 Chris Estrada, a friend of the killer, was sentenced to 42 months after his conviction for tampering with physical evidence. Dallas News, "Friend of man who killed Zuzu Verk in West Texas gets 3 1/2 years for evidence tampering," 12 July 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.

See More

First Known Use of killer

Noun

15th century, in the meaning defined at sense 1

Adjective

1951, in the meaning defined at sense 1

Keep scrolling for more

Keep scrolling for more

More Definitions for killer

killer

noun

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

killer

adjective

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

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

killer

noun
kill·​er | \ ˈki-lÉ™r 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

killer

adjective

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