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
Reduced soot buildup could help reusable launch providers lower maintenance demands and improve engine lifespan between launches.
—
Aamir Khollam, Interesting Engineering, 6 May 2026
Throughout its lifespan, the station has served as a test bed for scientific research in microgravity and has in years past opened itself up to private commercial missions.
—Eric Lagatta, USA Today, 6 May 2026
Over its 36-year lifespan, it’s been adjusted six times with little opposition.
—Sierra Lopez, Mercury News, 4 May 2026
That latter point is especially relevant for Hong Kong, which has some of the world’s longest lifespans and lowest birth rates.
—Brian Wong, Fortune, 3 May 2026
That was the average lifespan back in the 1800's, OK?
—John Ramos, CBS News, 3 May 2026
Several recent biomedical findings suggest that a profound link exists between an animal’s metabolism and its lifespan.
—Ross Andersen, The Atlantic, 2 May 2026
Eating a Mediterranean-style diet –– which focuses on fruits, vegetables, whole grains, nuts, seeds, healthy fish and extra-virgin olive oil, with smaller portions of eggs, dairy and poultry –– has been linked to significant increases in lifespan.
—Madeline Holcombe, CNN Money, 2 May 2026
Regularly replacing your lawn mower's air filter prevents engine damage, improves performance, and extends its lifespan.
—Kamron Sanders, Better Homes & Gardens, 2 May 2026
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Aamir Khollam, Interesting Engineering, 6 May 2026
Throughout its lifespan, the station has served as a test bed for scientific research in microgravity and has in years past opened itself up to private commercial missions.
—Eric Lagatta, USA Today, 6 May 2026
Over its 36-year lifespan, it’s been adjusted six times with little opposition.
—Sierra Lopez, Mercury News, 4 May 2026
That latter point is especially relevant for Hong Kong, which has some of the world’s longest lifespans and lowest birth rates.
—Brian Wong, Fortune, 3 May 2026
That was the average lifespan back in the 1800's, OK?
—John Ramos, CBS News, 3 May 2026
Several recent biomedical findings suggest that a profound link exists between an animal’s metabolism and its lifespan.
—Ross Andersen, The Atlantic, 2 May 2026
Eating a Mediterranean-style diet –– which focuses on fruits, vegetables, whole grains, nuts, seeds, healthy fish and extra-virgin olive oil, with smaller portions of eggs, dairy and poultry –– has been linked to significant increases in lifespan.
—Madeline Holcombe, CNN Money, 2 May 2026
Regularly replacing your lawn mower's air filter prevents engine damage, improves performance, and extends its lifespan.
—Kamron Sanders, Better Homes & Gardens, 2 May 2026
Cite this Entry
“Lifespan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lifespan. Accessed 9 May. 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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