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

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

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

Yet even if the entire world managed dramatic emission cuts, the fire would still burn 5.5% more intensely in 2050.

From The Wall Street Journal ● Aug. 12, 2026

“The conditions encourage speed. Removing the source of the odors is the primary objective here. However, that speed should not come at the detriment of the emission of odors or public health.”

From Los Angeles Times ● Aug. 6, 2026

The changes would mean some industries could obtain emission allowances until 2038 instead of 2034, if they commit to investing in decarbonisation efforts.

From BBC ● Jul. 17, 2026

The findings were published in Physical Review Letters in a paper titled "Resonant magnetophonon emission by supersonic electrons in ultrahigh-mobility two-dimensional systems," by Michael Hilke et al.

From Science Daily ● Jul. 2, 2026

One would therefore expect a system of massive objects to settle down eventually to a stationary state, because the energy in any movement would be carried away by the emission of gravitational waves.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

That figure is equivalent to about two thirds of the UK's total emissions for 2024.

From BBC ● Aug. 17, 2026

Nuclear power produces no greenhouse gas emissions, the primary driver of climate change.

From Los Angeles Times ● Aug. 16, 2026

The findings also raise the possibility that lowering emissions could have an additional role in protecting long-term human health.

From Science Daily ● Aug. 15, 2026

Its immediate effect was to wipe out federal vehicle emissions standards.

From Barron's ● Aug. 12, 2026

They had bombarded dozens of elements with deuterons and assiduously tracked emissions of alpha particles during the bombardments; but the continued emission of electrons or positrons after the bombardments ended had escaped their notice.

From "Big Science" by Michael Hiltzik

Related Words

• discharge
• radiation