time dilation

noun

Definition of time dilation

: a slowing of time in accordance with the theory of relativity that occurs in a system in motion relative to an outside observer and that becomes apparent especially as the speed of the system approaches that of light

called also time dilatation

Examples of time dilation in a Sentence

Recent Examples on the Web The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 The contribution upended understandings of gravity, space and time, opening up explorations of gravitational time dilation, light deflection and gravitational waves. Washington Post, 22 Nov. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'time dilation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of time dilation

1934, in the meaning defined above

Learn More About time dilation

Time Traveler for time dilation

Time Traveler

The first known use of time dilation was in 1934

See more words from the same year

Dictionary Entries Near time dilation

timed fire

time dilation

timed-release

See More Nearby Entries 

Statistics for time dilation

Last Updated

27 May 2022

Cite this Entry

“Time dilation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/time%20dilation. Accessed 28 May. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More from Merriam-Webster on time dilation

Britannica.com: Encyclopedia article about time dilation

WORD OF THE DAY

Test Your Vocabulary

Name That Food

  • a-light
  • Name these cookies!
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!