noun
life-or-death crisis; critical moment of survival
A formal, somewhat literary yojijukugo used to describe a situation where the very existence or survival of a person, group, or nation is at stake. Often appears in historical or dramatic contexts.
その国は危急存亡の時に立たされていた。
The nation was facing a life-or-death crisis.
危急存亡の秋に、彼は冷静な判断を下した。
At this critical moment of survival, he made a calm decision.