[ lahyf-tahym ]
See synonyms for lifetime on
  1. the time that the life of someone or something continues; the term of a life: peace within our lifetime.

  2. Physics. mean life.

  1. for the duration of a person's life: He has a lifetime membership in the organization.

Origin of lifetime

First recorded in 1175–1225, lifetime is from the Middle English word liftime.See life, time

Words Nearby lifetime Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use lifetime in a sentence

British Dictionary definitions for lifetime


/ (ˈlaɪfˌtaɪm) /

    • the length of time a person or animal is alive

    • (as modifier): a lifetime supply

  1. the length of time that something functions, is useful, etc

  1. physics the average time of existence of an unstable or reactive entity, such as a nucleus, excited state, elementary particle, etc; mean life

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