relativity

noun

rel·​a·​tiv·​i·​ty ˌre-lə-ˈti-və-tē How to pronounce relativity (audio)
plural relativities
1
a
: the quality or state of being relative
b
: something that is relative
2
: the state of being dependent for existence on or determined in nature, value, or quality by relation to something else
3
a
: 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 relativity

b
: an extension of the theory to include gravitation and related acceleration phenomena

called also general relativity, general theory of relativity

4

Examples of relativity in a Sentence

Recent Examples on the Web With space and time so intimately linked in relativity, any account of how space emerges must also explain time. Adam Becker, Scientific American, 1 Feb. 2022 This is reflected in the idea of linguistic relativity. Elpida Kokkota, Forbes, 4 Sep. 2024 The challenge for theorists is to find ways to unite the disparate theories of relativity and quantum mechanics in a theory of ‘loop’ quantum gravity that correctly predicts observations. The Physics Arxiv Blog, Discover Magazine, 31 July 2024 Because of effects explained by Albert Einstein’s theory of relativity, clocks tick ever-so-slightly faster on the Moon than on Earth, posing difficulties for communication and navigation. Byhannah Richter, science.org, 14 Aug. 2024 See all Example Sentences for relativity 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'relativity.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

circa 1834, in the meaning defined at sense 1a

Time Traveler
The first known use of relativity was circa 1834

Dictionary Entries Near relativity

Cite this Entry

“Relativity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/relativity. Accessed 31 Oct. 2024.

Kids Definition

relativity

noun
rel·​a·​tiv·​i·​ty ˌrel-ə-ˈtiv-ət-ē How to pronounce relativity (audio)
plural relativities
1
: the quality or state of being relative
especially : dependence on something else
2
a
: a theory in physics that considers mass and energy to be equal and that states that a moving object will experience changes in mass, size, and time which are related to its speed and are not noticeable except at speeds approaching that of light
b
: an extension of relativity theory to include gravity and its related acceleration effects
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