emis·​sion | \ ē-ˈmi-shən How to pronounce emission (audio) \

Definition of emission

1a : an act or instance of emitting : emanation
b archaic : publication
c : a putting into circulation
2a : something sent forth by emitting: such as
(1) : electromagnetic radiation from an antenna or a celestial body
(2) usually emissions : substances discharged into the air (as by a smokestack or an automobile engine)
b : effluvium

Other Words from emission

emissive \ ē-​ˈmi-​siv How to pronounce emission (audio) \ adjective

Examples of emission in a Sentence

trying to reduce the emission of greenhouse gases
Recent Examples on the Web There the Toyota Prius hybrid, which most popular where gas prices are high and emission regulations are strict, is the number one model. Jim Gorzelany, Forbes, 5 May 2022 The Yara Birkeland is what its builders call the world's first zero-emission, autonomous cargo ship. Jacopo Prisco, CNN, 5 May 2022 Nearly 12,000 feet above sea level and isolated in the Pacific Ocean, the Mauna Loa observatory is an ideal monitoring site because of its remoteness from both emission sources and carbon-absorbing forests, Dr. Tans said. Nidhi Subbaraman, WSJ, 5 May 2022 In 2009 and 2010 Chang and other astronomers found the first traces of the cosmic web in hydrogen’s 21-cm emission using radio telescopes in Australia and West Virginia. Ben Brubaker, Scientific American, 4 May 2022 During this period, the team found that the time lags between emission and echo were short and fast, lasting mere milliseconds. Jennifer Ouellette, Ars Technica, 2 May 2022 Eastern Utah’s Bonanza Power Plant, for example, will likely retire by 2030 due to a settlement with the U.S. Environmental Protection Agency over its emission controls. Leia Larsen, The Salt Lake Tribune, 1 May 2022 If emission trends can be reversed, however, there is greater hope for the future of the ocean’s ecosystems and biodiversity. Riley Black, Smithsonian Magazine, 28 Apr. 2022 By 2035, all would have to be zero-emission or alternative-fuel vehicles. Mark Pazniokas, Hartford Courant, 27 Apr. 2022 See More

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

First Known Use of emission

1607, in the meaning defined at sense 1a

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Time Traveler for emission

Time Traveler

The first known use of emission was in 1607

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Dictionary Entries Near emission



emission line

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Statistics for emission

Last Updated

12 May 2022

Cite this Entry

“Emission.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/emission. Accessed 24 May. 2022.

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More Definitions for emission


emis·​sion | \ ē-ˈmi-shən How to pronounce emission (audio) \

Kids Definition of emission

1 : the act of giving off The energy plant is reducing the emission of harmful gases.
2 : something that is given off Scientists can record radio emissions from far-off stars.


emis·​sion | \ ē-ˈmish-ən How to pronounce emission (audio) \

Medical Definition of emission

1 : an act or instance of emitting
2a : something sent forth by emitting: as
(1) : electrons discharged from a surface
(2) : electromagnetic waves radiated by an antenna or a celestial body
(3) : substances and especially pollutants discharged into the air (as by a smokestack or an automobile gasoline engine)
b : a discharge of fluid from a living body especially : ejaculate — see nocturnal emission


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