the time that the life of someone or something continues; the term of a life

peace within our lifetime.

Physics . mean life.

for the duration of a person's life

He has a lifetime membership in the organization.

noun

all one’s born days , career , continuance , course , cradle to grave , days , endurance , existence , life , life span , natural life , period , time , day , duration , span , term , age , being , forever