1.
one's life
A person's life, especially in contexts where life is at stake or has been saved. A literary and formal word used in dramatic or serious situations.
Usage
Almost always appears in the fixed phrase 一命を取り留める (to survive, to narrowly escape death). This is the most common and natural collocation. The word carries a literary, dramatic weight and is typical of news reports and formal writing.
Other patterns exist but are less common:
Register
Formal and literary. In everyday speech, 命 is the standard word for "life."