life span

American

noun

the longest period over which the life of any organism or species may extend, according to the available biological knowledge concerning it.
the longevity of an individual.

life span British

noun

the period of time during which a human being, animal, machine, etc, may be expected to live or function under normal conditions

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of life span

First recorded in 1915–20

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

If a disease is particularly rare or has a short life span, there isn’t much ‘water’ going into the tub, and there is a big drain on the other side.

From Barron's • Mar. 12, 2026

These burrow-dwelling rats have a maximum life span of nearly 40 years, making them world's the longest-lived rodent.

From BBC • Oct. 9, 2025

Technological advances may turn back aging, extending the average life span by at least a decade.

From The Wall Street Journal • Oct. 3, 2025

When Pes and his colleagues first visited Sardinia in the 1990s, they had speculated that the secret to the population’s longevity could be in their DNA—rare gene variants associated with an extended life span.

From Science Magazine • Nov. 20, 2024

Now he saw that his life span had always been determined by how long it took to eliminate all the Horcruxes.

From "Harry Potter and the Deathly Hallows" by J.K. Rowling

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023