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.
Lipski added that 15-to-20-year lifespan recommendation is for all fire departments across the country. Kelli Arseneau, jsonline.com, 20 Oct. 2025 Just remember to clean the rubber pads regularly to extend its lifespan. Kiana Murden, Vogue, 18 Oct. 2025 Since their birth in 1969, the Pads have had 23 managers, so their average lifespan on the bridge has been less than three years. Nick Canepa, San Diego Union-Tribune, 18 Oct. 2025 Plus, women face unique challenges such as caregiving responsibilities, longer lifespans, greater health care costs, and pay inequity, each of which impact their confidence in financial planning, according to the panelists. Dave Smith, Fortune, 17 Oct. 2025 The gene known as FOX03 may lead to having a smaller body size and a longer lifespan overall. Sherri Gordon, Health, 17 Oct. 2025 Improper washing and drying can reduce their effective lifespan. Nafeesah Allen, Better Homes & Gardens, 17 Oct. 2025 Sitting for too long during the day can compromise your health and shorten your lifespan. Fran Kritz, Verywell Health, 17 Oct. 2025 But from around 1988 to 1995, a number of labs identified a whole series of genes that, when mutated, could actually increase lifespan [in yeast and animals]. Dominique Mosbergen, Time, 16 Oct. 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 21 Oct. 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
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