life-threatening

adjective

life-threat·​en·​ing ˈlīf-ˌthre-tᵊn-iŋ How to pronounce life-threatening (audio)
-ˌthret-niŋ
: capable of causing death : potentially fatal
a life-threatening disease/condition
The injuries are serious but not life-threatening.

Examples of life-threatening in a Sentence

Recent Examples on the Web
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.
Even 4 to 6 inch amounts across the island chain will be dangerous and could cause mudslides and life-threatening flooding. — Marshall Shepherd, Forbes.com, 15 Aug. 2026 The five were transported to hospitals, and one initially listed as having life-threatening injuries has been upgraded to critical condition, county police said. — Patrick Whittle, Los Angeles Times, 15 Aug. 2026 Wasting – the most life-threatening form of acute malnutrition – is on the rise. — Kara Fox, CNN Money, 15 Aug. 2026 One person, a 21-year-old man who was initially listed as having life-threatening injuries, was upgraded to critical condition, police said in a news release Saturday night. — Nadine El-Bawab, ABC News, 15 Aug. 2026 See All Example Sentences for life-threatening

Word History

First Known Use

1759, in the meaning defined above

Time Traveler
The first known use of life-threatening was in 1759

Browse Nearby Words

life table
life-threatening
lifetime
See all Nearby Words

Cite this Entry

“Life-threatening.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/life-threatening. Accessed 17 Aug. 2026.

Copy Citation

Medical Definition

life-threatening

adjective
life-threat·​en·​ing ˈlīf-ˌthret-ən-iŋ How to pronounce life-threatening (audio)
: capable of causing death : potentially fatal
life-threatening injuries
a life-threatening allergic reaction
life-threatening arrhythmia
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of lackadaisical

See Definitions and Examples »

Popular in Grammar & Usage

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

7 Pairs of Commonly Confused Words

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Do you 'say your piece' or 'say your peace'?

Why is '-ed' sometimes pronounced at the end of a word?
See More

Popular in Wordplay

See More

Words from the 'Odyssey'

The Longest Long Words List

It's a Scorcher! Words for the Summer Heat

Is “GIF” Pronounced “Jiff” or “Giff”?

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

Words from the 'Odyssey'

The Longest Long Words List
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
image of a green cube out of place in a lineup of red spheres
Odd Word Out: Synonyms Vol. 2 Quiz Figure out which word isn't like the others.
See All