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.

The mystery patient reportedly needs retatrutide to treat obesity, sleep apnea, and pulmonary hypertension—a potentially life-threatening condition Trump hasn’t admitted to having.

From Slate • Jun. 23, 2026

A red heat alert is the highest of four warnings issued by Météo-France, and advises people to exercise extreme caution in conditions that are potentially life-threatening.

From BBC • Jun. 22, 2026

He announced "the tragic loss of 13 lives of our people who hold Indian and Pakistani nationalities. 66 people have been reported injured and are receiving medical treatment, none of whom are in life-threatening condition".

From Barron's • Jun. 22, 2026

Rates of diabetic ketoacidosis, a life-threatening complication that occurs when insulin levels are so low that cells can no longer convert glucose into energy, were three times that of the rest of Los Angeles County.

From Los Angeles Times • Jun. 14, 2026

Later, I learn that Azaan was taken to the temple’s infirmary with several injuries, but thankfully none that are life-threatening.

From "Beasts of Prey" by Ayana Gray