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

Keep scrolling for more

Synonyms for lifetime

Synonyms: Noun

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

Visit the Thesaurus for More 

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
See More

Recent Examples on the Web: Noun

The main culprit for Michigan’s high auto-insurance costs is its unique requirement that drivers purchase unlimited, lifetime medical benefits. WSJ, "States Put the Brakes on Car-Insurance Prices," 21 May 2019 Unfortunately, the rates of infant and childhood mortality were higher during Margaret Tudor's lifetime, and five of her children, including her first son, James, the Duke of Rothesay, died before the age of 2. Liz Cantrell, Town & Country, "How Margaret Tudor Became One of the Most Influential Queens in British History," 20 May 2019 Joe Raedle/Getty Images Widespread, sustained disasters like drought, wildfire, and flooding will affect virtually every human on the planet within their lifetimes, according to a dire new assessment of the global impacts of climate change. Alissa Walker, Curbed, "Cities have 15 months to reverse climate change, says new report," 8 Oct. 2018 Man jumps in, gets tangled in debris, officials say Missouri hikers were on 'trip of a lifetime' in Alaska. Joe Marusak, charlotteobserver, "Boy falls 30-60 feet down a steep NC waterfall — and lived," 10 July 2018 Kanye West is very kind and has given me the opportunity of a lifetime. Bianca Mercado, Billboard, "070 Shake on Working With Pusha-T, Kanye West's Tweets, and How Music Helps Her With Depression," 8 June 2018 But thanks to Senate Republicans and his lifetime appointment to the bench, Time will have decades to recognize that influence. Abby Gardner, Glamour, "The Time 100 List Includes Both Christine Blasey Ford and Brett Kavanaugh—and People Have Thoughts," 17 Apr. 2019 According to the College Scorecard, university graduates on average earn $1 million more over their lifetimes than high school graduates. Chuck Thompson, Popular Mechanics, "The State of American Trade Schools," 13 Mar. 2019 The Constitution provides Justices with lifetime appointments precisely to insulate them from political considerations. The Editorial Board, WSJ, "Behind the Supreme Court’s Dodge," 12 Dec. 2018

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.

See More

First Known Use of lifetime


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


1834, in the meaning defined at sense 1

Keep scrolling for more

Learn More about lifetime

Statistics for lifetime

Last Updated

25 May 2019

Look-up Popularity

Time Traveler for lifetime

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

See more words from the same century

Keep scrolling for more

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

Keep scrolling for more

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

Comments on lifetime

What made you want to look up lifetime? Please tell us where you read or heard it (including the quote, if possible).


to mark by some ceremony or observation

Get Word of the Day daily email!

Test Your Vocabulary

Challenging Vocabulary Quiz Returns!

  • stylized drawing of woman pole vaulting across gap to get trophy
  • Which is a synonym of fuliginous?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!