Life durations can be described in different ways depending on the context. Synonyms for life durations include lifespan, life expectancy, longevity, duration of life, time alive, years lived, age, length of existence, and time on earth. Lifespan and life expectancy refer to the average length of time individuals in a particular population are expected to live, while longevity pertains to exceptional long life. Duration of life, time alive, years lived, and age provide straight-forward descriptions of how long a person has been alive. Length of existence and time on earth capture the notion of time spent in this world. Regardless of the phrasing, all of these synonyms denote the amount of time that a living entity has lived or is expected to live.