emission

American  

[ih-mish-uhn] / ɪˈmɪʃ ən /

noun

• emissions
  plural

1. 

   an act or instance of emitting.

   the emission of poisonous fumes.

2. something that is emitted; discharge; emanation.

3. an act or instance of issuing, as paper money.

4. Electronics. a measure of the number of electrons emitted by the heated filament or cathode of a vacuum tube.

5. an ejection or discharge of semen or other fluid from the body.

   Synonyms:

   ejaculation

6. the fluid ejected or discharged.

   Synonyms:

   ejaculate

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emission British  

/ ɪˈmɪʃən /

noun

1. the act of emitting or sending forth

2. energy, in the form of heat, light, radio waves, etc, emitted from a source

3. a substance, fluid, etc, that is emitted; discharge

4. a measure of the number of electrons emitted by a cathode or electron gun See also secondary emission thermionic emission

   at 1000°C the emission is 3 mA

5. physiol any bodily discharge, esp an involuntary release of semen during sleep

6. an issue, as of currency

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Usage

What does emission mean? An emission is something that has been emitted—released or discharged. In general, emissions consist of things like gas, liquid, heat, sound, light, and radiation. Emissions can come from natural sources or from machines. A specific example of an emission is the exhaust from cars (in the U. S., such emissions are regulated through emissions tests). This exhaust is just one form of carbon emissions—greenhouse gases from various sources that are known to contribute to global warming and climate change. Emission can also refer to an instance or the process of emitting, as in This filter is designed to reduce the emission of light. Example: Carbon dioxide emissions from volcanoes are much lower than those from cars and airplanes.

Other Word Forms

Derived Forms

• nonemission
  noun
• reemission
  noun
• emissive
  adjective

Inflected Forms

Nouns

• emissions
  plural

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Etymology

Origin of emission

First recorded in 1600–10; from Middle French or directly from Latin ēmissiōn- (stem of ēmissiō ), equivalent to ēmiss(us), past participle of ēmittere “to send forth” ( ē- “from, out of” + mit-, stem of mittere “to send” + -tus past participle suffix) + -iōn- noun suffix; see origin at emit, e- ¹, -ion

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Explanation

An emission is something that's been released or emitted into the world. Car exhaust, burps, and radio broadcasts are all examples of emissions. Technically, an emission is anything that's been released out into the open. But more often it refers to gases being released into the air, like greenhouse gasses or emissions from power plants and factories. Anytime your body emits something (sweat, drool, gas), it's also considered an emission. Be careful not to confuse this word with the closely spelled omission — that's something that's been left out.

Example Sentences

See Examples For:

emission emissions

The unusual coherent X-ray emission could serve as a highly sensitive spectroscopic "sensor" for electron-electron correlations.

From Science Daily ● Oct. 29, 2026

They also point to the ultra low emission zone.

From BBC ● Oct. 24, 2026

She said the decision would "help minimise the UK's use of imported higher emission fuels as we continue our transition to renewables and nuclear".

From BBC ● Oct. 21, 2026

At home, Chinese brands are rapidly taking market share in Europe, while European automakers are struggling to meet EU emission targets and contending with surging energy costs that are sending manufacturing costs higher.

From The Wall Street Journal ● Oct. 16, 2026

In England, where emission controls barely exist, that rate has doubled.

From "All The Bright Places" by Jennifer Niven

He argued there was a "rational" case for further exploration if the project's carbon emissions was lower than using imported fuel.

From BBC ● Nov. 5, 2026

The massive energy demand makes distillation a major contributor to both fuel consumption and greenhouse gas emissions within the refining industry.

From Science Daily ● Nov. 5, 2026

"By replacing electricity that would otherwise come from fossil fuel-fired power plants, this output avoids 185,936 tonnes of carbon emissions each year," operator Sanko Enerji says.

From Barron's ● Nov. 5, 2026

Schwarzenegger, his former boss, ushered in the state’s landmark cap-and-invest program, which aims to reduce planet-warming emissions.

From Los Angeles Times ● Nov. 5, 2026

Their counter clicked; there were emissions just above the background level of radioactivity, but that was enough.

From "Big Science" by Michael Hiltzik

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Related Words

• discharge
• radiation

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