life-threatening

[lahyf-thret-ning, -thret-n-ing] / ˈlaɪfˌθrɛt nɪŋ, -ˌθrɛt n ɪŋ /

ADJECTIVE

very dangerous

Synonyms

STRONGEST

deadly lethal mortal serious severe

WEAK

capital critical hazardous threatening touch and go unsafe

Antonyms

STRONGEST

harmless invigorating

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A puppy is getting a new leash on life after being rescued with life-threatening facial injuries in Pasadena.

From Los Angeles Times • Apr. 7, 2026

The disorder causes constant, relentless hunger through hypothalamic dysfunction, where the brain fails to register fullness, often leading to life-threatening obesity.

From Barron's • Apr. 6, 2026

Such reactions can range from responses with “no clinical manifestations” to irritating rashes to life-threatening conditions such as anaphylactic shock, which constricts breathing and impairs motor function.

From Salon • Apr. 4, 2026

A headache can be benign or life-threatening depending on the context.

From The Wall Street Journal • Apr. 4, 2026

The eight-man expedition was pinned down in a ferocious blizzard high on K2, waiting to make an assault on the summit, when a team member named Art Gilkey developed thrombophlebitis, a life-threatening altitude-induced blood clot.

From "Into Thin Air" by Jon Krakauer