relativity

play
noun rel·a·tiv·i·ty \ˌre-lə-ˈti-və-tē\

Definition of relativity

plural

relativities

  1. 1a :  the quality or state of being relativeb :  something that is relative

  2. 2 :  the state of being dependent for existence on or determined in nature, value, or quality by relation to something else

  3. 3a :  a theory which is based on the two postulates (1) that the speed of light in a vacuum is constant and independent of the source or observer and (2) that the mathematical forms of the laws of physics are invariant in all inertial systems and which leads to the assertion of the equivalence of mass and energy and of change in mass, dimension, and time with increased velocity —called also special relativity, special theory of relativityb :  an extension of the theory to include gravitation and related acceleration phenomena —called also general relativity, general theory of relativity

  4. 4 :  relativism 1b

Circa 1834

First Known Use of relativity

circa 1834


RELATIVITY Defined for English Language Learners

relativity

play
noun rel·a·tiv·i·ty \ˌre-lə-ˈti-və-tē\

Definition of relativity for English Language Learners

  • physics : a theory developed by Albert Einstein which says that the way that anything except light moves through time and space depends on the position and movement of someone who is watching



Seen and Heard

What made you want to look up relativity? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

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

WORD OF THE DAY

capable of being altered or controlled

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

  • peter-bruegel-tower-of-babel-painting
  • What language does pajama come from?
True or False

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

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

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!