/ Dictionary / Index L lifetime: Meaning and Definition of Find definitions for: life•time Pronunciation: (līf'tīm"), [key] — n. the time that the life of someone or something continues; the term of a life: peace within our lifetime. See —adj. for the duration of a person's life: He has a lifetime membership in the organization. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lifetime (Thesaurus) life-threatening life vest Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language