lifespan

noun

life·​span ˈlīf-ˌspan How to pronounce lifespan (audio)
variants or less commonly life span
plural lifespans also life-spans
1
: the average length of life of a kind of organism or of a material object especially in a particular environment or under specified circumstances
2
: the duration of existence of an individual

Examples of lifespan in a Sentence

the average lifespan of house cats increase the human lifespan
Recent Examples on the Web
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.
Desert tortoises can live for decades, with a lifespan of up to 70 years in the wild and up to 100 years in captivity. John Leos, AZCentral.com, 18 July 2025 Psilocybin treatment extends cellular lifespan and improves survival of aged mice. Lucy Notarantonio, MSNBC Newsweek, 10 July 2025 Today, however, the virus has been replaced by drug overdoses and cardiovascular disease as the main causes driving down average lifespans. Los Angeles Times, 10 July 2025 But since the female flies only mate one time in their short, 20-day lifespan, once populations are exposed to sterile males, the populations die out over the course of months or years, depending on the size of the outbreak. Kameryn Griesser, CNN Money, 9 July 2025 During its 13-year lifespan, California’s clean car rebate program doled out nearly $1.5 billion in incentives, which helped residents buy more than 594,000 vehicles, according to state figures. David Lightman, Sacbee.com, 8 July 2025 Many groups are approaching the problem by trying to find a cost-effective way to shorten the lifespan of radioactive waste to tens or hundreds of years, through transmutation. IEEE Spectrum, 7 July 2025 Even if your kids only sometimes remember to use it, that could extend the likely lifespan of their headphones. Simon Hill Adrienne So, Wired News, 6 July 2025 As well, the museum will host a variety of programs throughout the exhibit's lifespan, including arts and crafts activities for families. Marcus K. Dowling, The Tennessean, 2 July 2025

Word History

First Known Use

1831, in the meaning defined at sense 2

Time Traveler
The first known use of lifespan was in 1831

Browse Nearby Words

Cite this Entry

“Lifespan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lifespan. Accessed 25 Jul. 2025.

Kids Definition

life span

noun
: the average length of life of a living thing or of the persistence of a material object under specified circumstances or in a particular environment

Medical Definition

life span

noun
1
: the duration of existence of an individual
2
: the average length of life of a kind of organism or of a material object especially in a particular environment or under specified circumstances
Last Updated: - Updated example sentences
Love words? Need even more definitions?

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