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.

See Examples For:

life-threatening

Researchers classified a severe medical outcome as one involving life-threatening effects, significant lasting disability, or death.

From Science Daily ● Aug. 18, 2026

At least three hurricanes have developed in the central and eastern Pacific since July, including Hurricanes Fausto and Genevieve, which generated life-threatening waves, strong rip currents and high surf warnings for Southern California.

From Los Angeles Times ● Aug. 18, 2026

However, the court rejected the appeal in July, with documents stating his medical condition was not "life-threatening" and added he would be able to access care in the UK.

From BBC ● Aug. 16, 2026

The heavy rainfall "will produce life-threatening flooding and mudslides, especially in areas of steep terrain."

From Barron's ● Aug. 15, 2026

But my illnesses have been minor and not life-threatening.

From "Counting by 7s" by Holly Goldberg Sloan