emission

Etymology

It is borrowed from Latin ēmissiō (“a sending out”) (accusative ēmissiōnem),^[2][3][4][5] a noun of action from ēmissus, the past participle of ēmittō (“to send out”),^[3][2][5] formed from ē- (“out”) and mittō (“to send, let go”).^[2][6] Barnhart and Etymonline also take it in part from Middle French émission,^[6][5] which Etymonline dates to the 14th century.^[5] The Anglo-Norman noun emission is recorded from the early 13th century for a discharge or release and for an offshoot.^[7] The verb emit is later, from 1626 in Bacon according to Barnhart, who thinks it was formed to give the noun a verb.^[6][5] The noun is related to emissary and mission.^[8][9][10]

Earliest recorded meaning

Something sent forth, a product or fruit: probably before 1425, in a translation of Higden's “Polychronicon”, according to Barnhart;^[6][11] Etymonline dates this sense to the early 15th century,^[5] and the Shorter Oxford and the ODE also date the word to late Middle English, in the sense of an emanation.^[9][12] The OED's first record is later, from 1607 in Edward Topsell, for the action of sending forth.^[2][13]

Semantic evolution

The general sense "the sending out of something or someone" became obsolete in the early 19th century;^[2][9] Hobbes could still speak of "the emission of preachers to the infidels".^[9] The physical sense, the giving off of light, heat, gases, odours or sounds, is recorded before 1619 in Donne according to Barnhart,^[6] and in the OED from 1626 in Bacon's “Sylva Sylvarum”.^[2] Johnson (1755) defined the word as "the act of sending out; vent", quoting Bacon.^[14] From 1646, in Sir Thomas Browne, it was used of the discharge of semen,^[2][9] and since 1664 of a thing emitted, an emanation.^[2] In money matters it meant the issuing of notes or shares from 1729, in Benjamin Franklin,^[2][13] and for a few decades it also meant the publication of a book.^[2][13] Physics gave it the emission theory of light (1831) and the giving off of radiation or particles, such as electrons from a cathode (1900, Rutherford).^[2][15] From 1966 emissions in the plural meant the pollutants and greenhouse gases released into the air by industry and vehicles.^[2]

Timeline

• probably before 1425 – something sent forth, produce.^[6]
• 1607 – the action of sending forth (obsolete by 1827).^[2]
• before 1619 – the giving off of something.^[6]
• 1646 – emission of semen.^[2]
• 1664 – that which is emitted, an emanation.^[2]
• 1729 – the issuing of notes, bills or shares.^[2]
• 1751 – the publication of a book (obsolete by 1779).^[2]
• 1831 – the emission theory of light.^[2]
• 1900 – the giving off of radiation or particles.^[2]
• 1966 – emissions, pollutants released into the air.^[2]

Modern meaning

Noun

1. The act of giving off or sending out something, such as heat, light, gas or sound: the emission of light from a distant galaxy.
2. Something that is given off, especially (usually plural) pollutants or greenhouse gases released into the air: The town plans to halve its carbon emissions.
3. (physics) The release of radiation or particles, as the flow of electrons from a cathode.
4. (physiology) A discharge from the body, especially of semen.
5. The issuing of currency, banknotes or shares.

Word family

• emissive
• nonemission
• photoemission
• reemission
• emission nebula
• emission spectrum
• field emission

Related words

• emit
• emissary
• mission

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
5. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
8. ^ Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
9. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
10. ^ Partridge, Eric (1966), Origins: A Short Etymological Dictionary of Modern English, 4th ed., London: Routledge & Kegan Paul
11. ^ Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
12. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
13. ^ a b c Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
14. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
15. ^ Collins English Dictionary (2023), Glasgow: HarperCollins