killer

American  

[kil-er] / ˈkɪl ər /

noun

1. a person or thing that kills. kill.

2. killer whale.

3. a device used by a post office for printing cancellations on postage stamps.

4. a mark of cancellation made on a postage stamp.

5. Slang. something or someone having a formidable impact, devastating effect, etc..

   The math test was a real killer.

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adjective

Slang.

1. severe; powerful.

   a killer cold.

2. very difficult or demanding.

   a killer chess tournament.

3. highly effective; superior.

   a killer recipe for fried chicken.

killer British  

/ ˈkɪlə /

noun

1. 1. a person or animal that kills, esp habitually

   2. ( as modifier )

      a killer shark

2. something, esp a task or activity, that is particularly taxing or exhausting

3. an animal selected to be slaughtered for food

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Usage

What is a basic definition of killer? A killer is a person or thing that kills, meaning they end lives. Killer is also used in slang to mean something that is devastating or exhausting. Additionally, killer is used in slang to describe something as severe or powerful. Killer has several other meanings as a noun and an adjective.A person or thing that ends someone’s life is a killer. In terms of a person, killer is often used interchangeably with murderer. However, killer can refer to someone who killed another person by accident, while murderer is not used in that sense.

• Real-life examples: John Wilkes Booth was Abraham Lincoln’s killer. Jack the Ripper was an infamous killer. Bacteria and viruses often act as natural killers. People use weed killers on their lawns.
• Used in a sentence: My cat is a very effective killer of birds.

In slang, killer is used to describe something as causing stress, exhaustion, pain, or misery.

• Real-life examples: You might call a particularly hard test a killer test. A killer workout would push your body to the limits of its abilities.
• Used in a sentence: That history assignment turned out to be a killer and took me forever to finish.

In slang, killer is also used to describe something as severe, intense, or powerful.

• Real-world examples: You might call a baseball game that goes into extra innings with a 2–2 score, a killer game. If you come down with a severe cold that keeps you in bed for several days, you could call it a killer cold.
• Used in a sentence: After living abroad for five years, Michelle came down with a killer case of homesickness.

Other Word Forms

• self-killer noun

Etymology

Origin of killer

First recorded in 1525–35; kill ¹ + -er ¹

Example Sentences

And its recipe was a killer combo of the two things we love so much: cars, and sunlight.

From Los Angeles Times

Sanjoy said he had asked specifically whether a hair sample was taken from the killer, after he refused blood and urine testing.

From BBC

In fact, Flaherty said the person doing the MIT interview admitted later, “I’m not going to lie. I thought that was the killer for your application.”

From Los Angeles Times

Last year, 7 million people around the world, 600,00 of them children, died from a slow-moving, silent and largely invisible killer: air pollution.

From Salon

But the killer was hiding in plain sight – McCullagh was not only at the rally but he had put together a montage of home videos of Natalie, which were displayed on big screens.

From BBC