the act of prolonging one's life
to shorten one's life―shorten one's days―shorten one's natural term of existence―drive a nail in one's coffin
the condition of taking or assuming a new lease on life and thus being able to expand one's life span
to prolong one's life―lengthen one's days―add to one's natural term of existence―take a new lease of life
the time period during which a thing lasts
寿命.
His days are numbered.