1
a
: 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)
b
2
: an amount accumulated or experienced in a lifetime
a lifetime of regrets
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
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
Recent Examples on the Web
Kaif Shaikh, Interesting Engineering, 26 Sep. 2025
This once-in-a-lifetime cosmic event happens approximately every 50 years when the centaur Chiron returns to its home sign and degree, which is when the movie came out.
—Lisa Stardust, PEOPLE, 26 Sep. 2025
Stephan Rabimov, Forbes, 24 May 2021
They are viewed as the most restrictive among the 15 states with consecutive or lifetime legislative term limits.
—David Eggert, Detroit Free Press, 20 Nov. 2019
See All Example Sentences for lifetime
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Noun
Can Optimus deliver more value than its total cost of ownership over the lifetime compared with existing automation alternatives?
—Kaif Shaikh, Interesting Engineering, 26 Sep. 2025
This once-in-a-lifetime cosmic event happens approximately every 50 years when the centaur Chiron returns to its home sign and degree, which is when the movie came out.
—Lisa Stardust, PEOPLE, 26 Sep. 2025
Adjective
Getting an Emmy award is a lifetime dream for many.
—Stephan Rabimov, Forbes, 24 May 2021
They are viewed as the most restrictive among the 15 states with consecutive or lifetime legislative term limits.
—David Eggert, Detroit Free Press, 20 Nov. 2019
See All Example Sentences for lifetime
Cite this Entry
“Lifetime.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lifetime. Accessed 29 Sep. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share