Vital to the resolution of a crisis or the determination of an outcome:
Extremely important or essential:
The definition of important is having great significance or consequence.
Find another word for life-or-death. In this page you can discover 7 synonyms, antonyms, idiomatic expressions, and related words for life-or-death, like: crucial, necessary, critical, important, life-and-death, long-drawn-out and decisive.