[ ih-mish-uhn ]
/ ɪˈmɪʃ ən /
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See synonyms for: emission / emissions on Thesaurus.com

an act or instance of emitting: the emission of poisonous fumes.
something that is emitted; discharge; emanation.
an act or instance of issuing, as paper money.
Electronics. a measure of the number of electrons emitted by the heated filament or cathode of a vacuum tube.
an ejection or discharge of semen or other fluid from the body.
the fluid ejected or discharged.
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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


non·e·mis·sion, nounre·e·mis·sion, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


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 emissionsgreenhouse 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.

Where does emission come from?

The first records of the word emission come from the early 1600s. It ultimately derives from the Latin verb ēmittere, from e-, meaning “out of,” and mittere, “to send.”

An emission is something sent out from something else. Such emissions are often by-products released during the course of other processes—such as smoke being emitted from a factory or heat being emitted from a machine. Emissions from cars and airplanes come from the burning of fuel by their engines. In physics and electronics, the word is used in a more specific way to refer to the amount of electrons being emitted from an object.

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What are some other forms related to emission?

  • emissive (adjective)
  • nonemission (noun)
  • reemission (verb)
  • emit (verb)

What are some synonyms for emission?

What are some words that share a root or word element with emission

What are some words that often get used in discussing emission?

How is emission used in real life?

Emissions are usually discussed in technical or scientific contexts.



Try using emission!

An emission can consist of which of the following things?

A. liquid
B. gas
C. sound
D. all of the above

How to use emission in a sentence

British Dictionary definitions for emission

/ (ɪˈmɪʃən) /

the act of emitting or sending forth
energy, in the form of heat, light, radio waves, etc, emitted from a source
a substance, fluid, etc, that is emitted; discharge
a measure of the number of electrons emitted by a cathode or electron gunat 1000°C the emission is 3 mA See also secondary emission, thermionic emission
physiol any bodily discharge, esp an involuntary release of semen during sleep
an issue, as of currency

Derived forms of emission

emissive, adjective

Word Origin for emission

C17: from Latin ēmissiō, from ēmittere to send forth, emit
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012