life·​time | \ ˈlīf-ˌtīm How to pronounce lifetime (audio) \

Definition of lifetime

 (Entry 1 of 2)

1a : the duration of the existence of a living being (such as a person or an animal) or a thing (such as a star or a subatomic particle)
2 : an amount accumulated or experienced in a lifetime a lifetime of regrets



Definition of lifetime (Entry 2 of 2)

1 : lifelong
2 : of long duration or continuance lifetime legislation
3 : measured or achieved over the span of a career a baseball player's lifetime batting average

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Synonyms for lifetime

Synonyms: Noun

continuance, date, duration, life, life span, run, standing, time

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Examples of lifetime in a Sentence


a lifetime spent traveling the world It would have taken me a lifetime to read all those books. Childhood seems a lifetime ago now! a chemical with a lifetime of only a few minutes the lifetime of a planet
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Recent Examples on the Web: Noun

The ongoing success of the Laguna Beach girls’ volleyball team could be credited, in no small part, to chemistry that has been forming over a lifetime. Andrew Turner, Daily Pilot, "High School Female Athlete of the Week: Piper Naess powers Laguna Beach volleyball up the CIF poll," 13 Sep. 2019 Further to this, La Blaugrana are reportedly ready to hand him a 'lifetime' contract even after his playing days draw to a close., "Diego Maradona Reveals the Shooting Advice He Gave to Lionel Messi at 2010 World Cup," 10 Sep. 2019 Leake who has pitched for four teams since being traded to the Giants on July 30, 2015 for Adam Duvall and right-hander Keury Mella, is 0-5 lifetime against the Reds. Jeff Wallner,, "Michael Lorenzen's late-game heroics powers Cincinnati Reds over Arizona Diamondbacks," 8 Sep. 2019 Mancini, who has a lifetime 29-5-0 record with 23 knockouts, held the World Boxing Association lightweight title 1982-84. Marc Bona,, "Cleveland Whiskey hosting ‘Boom Boom’ Mancini, eyes expansion," 6 Sep. 2019 Alicia Trost, BART’s director of communications, told me that the system didn’t track the total amount Tiny Tickets has collected over the project’s lifetime. Caille Millner,, "No more BART paper, so no more charity?," 5 Sep. 2019 There should be no difference (other than mass and lifetime) between the electron and the muon, theoretically. Jennifer Ouellette, Ars Technica, "Physics not “broken” after all? We’re close to resolving proton radius puzzle," 5 Sep. 2019 That’s for the best, and not just because the past three years of public life have inspired enough pedantic art for three lifetimes. Judy Berman, Time, "Review: Norman F---ing Rockwell! Is Lana Del Rey's Darkest—And Greatest—Album Yet," 30 Aug. 2019 Most sputter out or dribble away; few last a lifetime. Stephen Galloway, The Hollywood Reporter, "Why Nobody in Hollywood Has Any Friends," 30 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'lifetime.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of lifetime


13th century, in the meaning defined at sense 1a


1834, in the meaning defined at sense 1

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Statistics for lifetime

Last Updated

12 Oct 2019

Look-up Popularity

Time Traveler for lifetime

The first known use of lifetime was in the 13th century

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More Definitions for lifetime



English Language Learners Definition of lifetime

: the time during which a person is alive
: a very long time
: the time during which something lasts or is useful


life·​time | \ ˈlīf-ˌtīm How to pronounce lifetime (audio) \

Kids Definition of lifetime

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More from Merriam-Webster on lifetime

Rhyming Dictionary: Words that rhyme with lifetime

Thesaurus: All synonyms and antonyms for lifetime

Spanish Central: Translation of lifetime

Nglish: Translation of lifetime for Spanish Speakers

Britannica English: Translation of lifetime for Arabic Speakers

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