lifetime
Americannoun
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lifetimes
plural
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the time that the life of someone or something continues; the term of a life.
peace within our lifetime.
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Physics. mean life.
adjective
noun
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the length of time a person or animal is alive
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( as modifier )
a lifetime supply
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the length of time that something functions, is useful, etc
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physics the average time of existence of an unstable or reactive entity, such as a nucleus, excited state, elementary particle, etc; mean life
Other Word Forms
Noun Inflected Forms
Etymology
Origin of lifetime
First recorded in 1175–1225, lifetime is from the Middle English word liftime. See life, time
Explanation
A lifetime is the entire length of time a person or other living thing is alive. After a famous actor dies, she may be fondly remembered for a lifetime of great movie roles. Things that take up most of the duration of a person's life are often described using the word lifetime, like a terrible driver's lifetime ban on holding a driver's license, or a lifetime achievement award for all of your accomplishments. You can also talk about the lifetime of an object, or the length of time it's useful, and use lifetime figuratively, to mean "a very long time."
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
To Mona, this thankless part is the opportunity of a lifetime.
From Los Angeles Times ● Sep. 18, 2026
Their lifetime is so short that any significant delay would prevent them from reaching the surface before they decay.
From Science Daily ● Sep. 18, 2026
Mr. Musk, the greatest entrepreneur of my lifetime, was right about the mission.
From The Wall Street Journal ● Sep. 16, 2026
Cristiano Ronaldo, who plays for Al-Nassr in Saudi Arabia and was an international team-mate of Jota, called for lifetime bans to be issued to the chanting fans.
From BBC ● Sep. 16, 2026
“Success is counted sweetest” was one of the few poems that was published during her lifetime, but only anonymously, and no one knows if she gave permission.
From "Keeping Pace" by Laurie Morrison
The boss of the biggest UK-headquartered tech firm has said that artifical intelligence will find a cure for cancer that humans cannot in our lifetimes.
From BBC ● Sep. 7, 2026
On some occasions, albeit rare but possible given extended lifetimes, an aging parent will move into a retirement community after their boomer kids.
From The Wall Street Journal ● Sep. 5, 2026
Now, 12 years and many political lifetimes later, they read as quaint and out-of-touch, like a grandfather telling his grandson to never contradict his betters.
From Salon ● Aug. 20, 2026
L.A. arts patrons Betty Freeman and Richard Colburn provided important support for Salzburg during their lifetimes that included commissioning new work.
From Los Angeles Times ● Aug. 5, 2026
A lot of kids, I was coming to realize, had never in their lifetimes known anything different.
From "Becoming" by Michelle Obama
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
