noun
one life; a life
Refers to a single human life, often in contexts of life and death, survival, or sparing a life.
彼は一命を取り留めた。
He barely escaped with his life.
一命を救うために全力を尽くした。
We did everything we could to save a life.
noun
one order; one command
Used in military or organizational contexts for a single command or directive.
将軍の一命で兵士たちは進軍を開始した。
At the general's single command, the soldiers began their advance.