Definitions

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.

They made it to a nearby clinic, San Antonio de Catia La Mar, where the besieged staff was implementing emergency triage, prioritizing those with life-threatening conditions.

From Los Angeles Times • Jun. 30, 2026

Their fundraiser for Molly Ollys, a Warwick-based charity that supports children with life-threatening illnesses, has now well exceeded its £5,000 target, surpassing £11,000.

From BBC • Jun. 30, 2026

None of their injuries were life-threatening or life-changing, according to the Met.

From BBC • Jun. 29, 2026

London Ambulance Service said the extreme heat on Wednesday led to the highest number of life-threatening emergency calls in a day.

From Barron's • Jun. 25, 2026

Whenever Keisha showed worrisome symptoms, the Merritts acted as if it was a life-threatening emergency, which made me feel left out.

From "Three Little Words: A Memoir" by Ashley Rhodes-Courter