|1.||a. the length of time a person or animal is alive|
|b. (as modifier): a lifetime supply|
|2.||the length of time that something functions, is useful, etc|
|3.||physics the average time of existence of an unstable or reactive entity, such as a nucleus, excited state, elementary particle, etc; mean life|
lifetime life·time (līf'tīm')
The period of time during which an individual is alive.
The period of time during which property, an object, a process, or a phenomenon exists or functions.