life-threatening

adjective

life-threat·​en·​ing ˈlīf-ˌthre-tᵊn-iŋ 

-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

Lindsey Graham died unexpectedly July 11 from a life-threatening condition caused by a tear in his aorta, the body's main artery. — Michael Smith, USA Today, 18 July 2026

As body temperature rises and humidity limits the body’s ability to cool itself, mild symptoms such as cramps and headaches can progress to shortness of breath, dizziness, confusion, nausea, and ultimately life-threatening heat stroke. — Laura Schifter, Time, 17 July 2026

In its first phase, the program offers genomic testing to 50,000 adults, screening for inherited predispositions to three major life-threatening diseases. — William A. Haseltine, Forbes.com, 17 July 2026

The three were taken to a hospital with injuries that were not considered life-threatening, police said. — Darrell Smith, Sacbee.com, 17 July 2026

Word History

First Known Use

1759, in the meaning defined above

Medical Definition

life-threatening

adjective

life-threat·​en·​ing ˈlīf-ˌthret-ən-iŋ 

: capable of causing death : potentially fatal

life-threatening injuries

a life-threatening allergic reaction

life-threatening arrhythmia