• span of a person's life, time during which a person is alive; period of time during which something functions or exists
• a lifetime is the length of time that someone is alive.
• the lifetime of something is the period of time that it lasts.
chance of a lifetime
• opportunity that will never come again, rare opportunity
• the days of his life, the duration of his life, the days of his existence
legacy during lifetime
• property that is transferred before the death of the testator
once in a lifetime
• extremely rare, will never happen again