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
Lorenzino Estrada, AZCentral.com, 23 July 2025
Prepare to screenshot your best replies Look out for when someone leaves a killer testimonial in your comments.
—Jodie Cook, Forbes.com, 21 July 2025
The series was based on the real-life story of Melissa G. Moore, who found out at 15 years old that her father was actually an infamous serial killer who went by the name of Happy Face.
—Andy Swift, TVLine, 21 July 2025
In the dramatic conclusion to Season 2, Colter finally uncovered the mystery man behind his father’s killer, but not without unfolding a series of questions, including his mother’s involvement in the death.
—Natalie Oganesyan, Deadline, 19 July 2025
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
In 1991: Serial killer and cannibal Jeffrey Dahmer was arrested by two Milwaukee police officers, Robert Rauth and Rolf Mueller.
—Lorenzino Estrada, AZCentral.com, 23 July 2025
Prepare to screenshot your best replies Look out for when someone leaves a killer testimonial in your comments.
—Jodie Cook, Forbes.com, 21 July 2025
The series was based on the real-life story of Melissa G. Moore, who found out at 15 years old that her father was actually an infamous serial killer who went by the name of Happy Face.
—Andy Swift, TVLine, 21 July 2025
In the dramatic conclusion to Season 2, Colter finally uncovered the mystery man behind his father’s killer, but not without unfolding a series of questions, including his mother’s involvement in the death.
—Natalie Oganesyan, Deadline, 19 July 2025
See All Example Sentences for killer
Cite this Entry
“Killer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/killer. Accessed 29 Jul. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share