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

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Examples of lifetime in a Sentence

Noun 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 Help didn’t come in 2008, but then came the pandemic — truly a once-in-a-lifetime cataclysm. Los Angeles Times, "How a COVID-era Federal Writers Project went from wild idea to a proposed bill," 6 May 2021 To be on something that was critically acclaimed, and also very popular globally, is a once-in-a-lifetime experience. Jim Clash, Forbes, "‘Grey’s Anatomy’ Star Kate Walsh On Coral Reef Restoration, And Her TV Character Addison Montgomery," 5 May 2021 For aerial photographer Tom Hegen, however, the disruption caused to the world's airports by Covid-19 offered a once-in-a-lifetime opportunity. CNN, "Aerial photos reveal hidden beauty of airports," 4 May 2021 Wiley has a solid set of ideas aimed toward the monumental task of rebuilding the city after a (hopefully) once-in-a-lifetime crisis. Natalie Gontcharova,, "Can Maya Wiley Break New York City’s Glass Ceiling?," 4 May 2021 Some pulled up chairs and others plopped down on a black faux-leather sofa to describe what this once-in-a-lifetime school year has been like. New York Times, "Denied a Season, Some Ivy League Athletes Craft a Baseball Gap Year," 2 May 2021 The once-in-a-lifetime allure brought in Aretha Duncan, 53, and her 21-year-old daughter, Autumn Duncan, to Cleveland from Youngstown. Cameron Fields, cleveland, "Fans enjoy final day of NFL Draft Experience with perfect Cleveland weather," 1 May 2021 Troop 387 is raising funds for a once-in-a-lifetime 10-day canoeing and camping trip in the Boundary Waters Wilderness Area between Minnesota and Canada, as well as new troop equipment and other camping and scouting activities., "Community news for the Enfield edition," 30 Apr. 2021 The route that leads to Machu Picchu is a once-in-a-lifetime trek that follows the footsteps of a great lost civilization. Evie Carrick, Travel + Leisure, "8 Best Backpacking Trips Around the World," 25 Apr. 2021 Recent Examples on the Web: Adjective In addition to keynote speeches, panel discussions, workshops and networking, the 2019 Music Biz conference will again take time to recognize both recent and lifetime achievements. Gary Graff, Billboard, "Inside Music Biz 2019: The Power Summit's Chief James Donio On Six Decades Of Industry Shake-Ups & Top Concerns Today," 29 Apr. 2019 They are viewed as the most restrictive among the 15 states with consecutive or lifetime legislative term limits. David Eggert, Detroit Free Press, "Former Michigan lawmakers sue to block legislative term limits," 20 Nov. 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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Time Traveler for lifetime

Time Traveler

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

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Statistics for lifetime

Last Updated

11 May 2021

Cite this Entry

“Lifetime.” Dictionary, Merriam-Webster, Accessed 12 May. 2021.

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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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