Added 8 October 2026 lifespan /ˈlaɪf.spæn/ noun Categories: TimeRare Words noun ! Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about lifespan at Wordnik → Where our words come from → The period during which something is functional (as between birth and death). the battery had a short life Origin From life + span. From Wiktionary, via Kaikki.org (CC BY-SA) Related Words: lifetimelifeageslongevitydurabilitylivingperiodlifecycledurationexistencetermexpectancy Back to today's word