life-and-death

[lahyf-uh n-deth] /ˈlaɪf ənˈdɛθ/
adjective
1.
ending with the death or possible death of one of the participants; crucially important:
The cobra was engaged in a life-and-death struggle with the mongoose.
Also, life-or-death.
Origin
1680-90
Idioms and Phrases with life and death

life and death