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.

The technology is advancing so fast, moreover, that there may be a payoff both in life span and “health span,” your time actually living without serious disease.

From Barron's • May 21, 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

The Mediterranean island, they thought, offered ideal conditions for studying the genes and habits that can influence life span: Its population is relatively isolated, with low rates of immigration and little genetic diversity.

From Science Magazine • Nov. 20, 2024

For twenty years, over the entire life span of the revolutionary war and the experiment with republican government, Washington had stood at the helm of the ship of state.

From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis

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