n (uncountable) That part of the duration of a being or a thing which is between its beginning and any given time; specifically the size of that part.
n (uncountable) The latter part of life; an advanced period of life, eld; seniority; state of being old.
n (uncountable) Mature age; especially, the time of life at which one attains full personal rights and capacities.
n (countable) The time of life at which some particular power or capacity is understood to become vested.