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
Buffett concluded his letter by saying it had been the "privilege of a lifetime" to serve as chairman, but acknowledged that in the end, "Father Time always wins".
From BBC ● Sep. 18, 2026
An exceptionally precise first mid-course correction, combined with other fuel savings, could more than double the observatory's potential lifetime in space.
From Science Daily ● Sep. 18, 2026
Mr. Wittman, an avuncular, white-haired 70-year-old of medium height—self-described as “nondescript,” which he noted is an asset for going undercover—has seen a lot of museums in his lifetime.
From The Wall Street Journal ● Sep. 15, 2026
He'd just made the shot of a lifetime in front of thousands of people, and for the first time in a week, he actually hadn't been thinking about money.
From "Millionaires for the Month" by Stacey McAnulty
“You can see in real time people thinking, ‘Wait, the best-case scenario is the largest economic and social disruption of our lifetimes and the worst-case scenario is an existential risk to humanity.’”
From The Wall Street Journal ● Sep. 11, 2026
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
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
Researchers say amphibians provide a window into the past because they don’t travel far during their lifetimes and are sensitive to climate change.
From Los Angeles Times ● Aug. 7, 2026
And a vuvv lawsuit will ruin us—vuvv law costs people more than they will earn in twelve lifetimes.
From "Landscape with Invisible Hand" by M.T. Anderson
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.
