killer

1 of 2

noun

kill·​er ˈki-lər 

1

: one that kills

2

: killer whale

3

a

: one that has a forceful, violent, or striking impact

b

: one that is extremely difficult to deal with

killer

2 of 2

adjective

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

Synonyms

Noun

• bear
• beast
• chore
• headache
• job
• labor

Adjective

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

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

Noun

The unknown killer becomes a twisted sensation on social media. —Chris Kenning, USA TODAY, 12 Dec. 2024

The unit is dedicated to studying the behavior of serial killers and other types of criminals. —Gordon G. Chang, Newsweek, 11 Dec. 2024

Accused Ivy League killer's mind may have been driven by ObamaCare fine print, former FBI agent says. —Fox News, 11 Dec. 2024

Music How Laci Kaye Booth survived Nashville to make a killer country album May 22, 2024 4. —Mikael Wood, Los Angeles Times, 11 Dec. 2024

Word History

First Known Use

Noun

15th century, in the meaning defined at sense 1

Adjective

1951, in the meaning defined at sense 1

Phrases Containing killer

• killer app
• killer bee
• killer cell
• killer instinct
• killer T cell
• killer T lymphocyte
• killer whale
• lady-killer
• natural killer cell
• pain-killer
• time killer

Kids Definition

killer

1 of 2 noun

ˈkil-ər

1

: one that kills

2

: killer whale

killer

2 of 2 adjective

1

: strikingly impressive or effective

a killer smile

2

: extremely difficult

a killer exam

also : causing death or devastation

a killer tornado