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
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
Matt Cabral, Entertainment Weekly, 15 June 2026
That film served as Carpenter’s follow-up to his breakthrough hit, Halloween, which didn’t invent the slasher film but did codify and popularize the horror subgenre in which seemingly deathless masked killers stalk helpless prey, often horny teens (though anyone will do in a pinch).
—Keith Phipps, Vulture, 15 June 2026
Heuermann has been a voracious reader in jail, but Toulon said the inmate’s preference for violent crime and mystery novels — some about serial killers — concerns him.
—Philip Marcelo, Fortune, 15 June 2026
Experts also nod to the effects of social media—many young people now socialize online rather than in person—the way the 2020–22 homicide spike took potential killers off the street, and even the possible influence of GLP-1 weight loss drugs, which may diminish impulsive behaviors.
—The Week Us, TheWeek, 15 June 2026
See All Example Sentences for killer
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
On top of doggedly tracking a serial killer whose murder spree started decades earlier, our shrewd heroine uncovers a tangled workplace conspiracy that's as sinister as her prime suspect's motives.
—Matt Cabral, Entertainment Weekly, 15 June 2026
That film served as Carpenter’s follow-up to his breakthrough hit, Halloween, which didn’t invent the slasher film but did codify and popularize the horror subgenre in which seemingly deathless masked killers stalk helpless prey, often horny teens (though anyone will do in a pinch).
—Keith Phipps, Vulture, 15 June 2026
Heuermann has been a voracious reader in jail, but Toulon said the inmate’s preference for violent crime and mystery novels — some about serial killers — concerns him.
—Philip Marcelo, Fortune, 15 June 2026
Experts also nod to the effects of social media—many young people now socialize online rather than in person—the way the 2020–22 homicide spike took potential killers off the street, and even the possible influence of GLP-1 weight loss drugs, which may diminish impulsive behaviors.
—The Week Us, TheWeek, 15 June 2026
See All Example Sentences for killer
Cite this Entry
“Killer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/killer. Accessed 16 Jun. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
