lifespan
noun
life·span
ˈlīf-ˌspan 
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
Unlike other models, the gel fibers offer a bounce-back effect that allows your pillows to keep their fluffy shape for an even longer lifespan.
—
Megan Schaltegger, PEOPLE, 7 Jan. 2026
Their average lifespan is about 15 years.
—Saleen Martin, USA Today, 5 Jan. 2026
The implications of the breakthrough are enormous – not only for lifespan, but for healthspan, says Antonyak.
—New Atlas, 4 Jan. 2026
Unfortunately, there's no evidence that resveratrol or rapamycin improves human lifespans.
—CBS News, 3 Jan. 2026
Unfiltered water, Adams insists, leads to sediment buildup in your water heater, which shortens its lifespan and lessens its heating efficiency.
—Quincy Bulin, Southern Living, 3 Jan. 2026
Now, Scieszka’s debut filters Tuck Everlasting-esque immortality through the social media age—examining how someone hides their eternal lifespan from facial recognition technology and venture capitalists looking to capitalize upon family property and the ultimate anti-aging secrets.
—Literary Hub, 2 Jan. 2026
Technician Rich Cox has witnessed the entirety of The Stereo Shop’s lifespan, starting as a customer more than a half century ago.
—Tribune News Service, Baltimore Sun, 2 Jan. 2026
Exercise has been shown to help elevate mood and reduce the risk of cognitive decline in older adults, with some research finding that physical activity level is the single biggest predictor of lifespan after the age of 50.
—Emma Loewe, Outside, 1 Jan. 2026
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Megan Schaltegger, PEOPLE, 7 Jan. 2026
Their average lifespan is about 15 years.
—Saleen Martin, USA Today, 5 Jan. 2026
The implications of the breakthrough are enormous – not only for lifespan, but for healthspan, says Antonyak.
—New Atlas, 4 Jan. 2026
Unfortunately, there's no evidence that resveratrol or rapamycin improves human lifespans.
—CBS News, 3 Jan. 2026
Unfiltered water, Adams insists, leads to sediment buildup in your water heater, which shortens its lifespan and lessens its heating efficiency.
—Quincy Bulin, Southern Living, 3 Jan. 2026
Now, Scieszka’s debut filters Tuck Everlasting-esque immortality through the social media age—examining how someone hides their eternal lifespan from facial recognition technology and venture capitalists looking to capitalize upon family property and the ultimate anti-aging secrets.
—Literary Hub, 2 Jan. 2026
Technician Rich Cox has witnessed the entirety of The Stereo Shop’s lifespan, starting as a customer more than a half century ago.
—Tribune News Service, Baltimore Sun, 2 Jan. 2026
Exercise has been shown to help elevate mood and reduce the risk of cognitive decline in older adults, with some research finding that physical activity level is the single biggest predictor of lifespan after the age of 50.
—Emma Loewe, Outside, 1 Jan. 2026
Cite this Entry
“Lifespan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lifespan. Accessed 7 Jan. 2026.
Copy CitationMedical Definition
lifespan
noun
variants
also life span
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
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