emulsion

Etymology

It is borrowed from New Latin ēmulsiō,^{[2][3][4][5][6]} and perhaps also borrowed from French émulsion, recorded in the 16th century.^{[7][8][9][10]} The New Latin noun is formed on Latin ēmulsus (“milked out”), the past participle of ēmulgeō (“to milk out, drain out”),^{[3][8][7][11]} from ē- (“out”), a form of ex, and mulgeō (“to milk”),^[3][7][8] from Proto-Indo-European *melg- (“to rub off; to milk”),^[7][3] the root of milk.^[6][8]

Earliest recorded meaning

A milky liquid made by bruising almonds or the like in water: 1612, in P. Pomarius's Enchiridion.^[2][12][13] Barnhart and Merriam-Webster Unabridged also date the word to 1612,^[8][4] Etymonline to the 1610s.^[7]

Semantic evolution

Johnson (1755) still defined it as "a form of medicine, by bruising oily seeds and kernels".^[14] It later came to mean any mixture of two liquids that do not dissolve in each other, one spread through the other in small droplets, of which milk is the classic example.^[10][7][6] Robinson's Endoxa (1658) has a one-off figurative use, the action of "milking out".^[2] The derivative emulsify follows in 1859.^[8] In photography, the word has been used for a silver compound held in collodion or gelatin since 1840, in Herschel.^[2][7] Ayto dates the application to paint to the 1930s,^[6] and the Shorter Oxford to the mid 20th century, when the noun also became a verb, to paint with emulsion paint.^[10] According to the Oxford Dictionary of Word Origins, this household paint is now what most people think of first.^[13]

Timeline

• 1612 – a milky liquid made by bruising almonds or the like in water.^[2][4]
• 1658 – figuratively, the action of milking out (obsolete).^[2]
• mid 18th century – verb, to emulsify (now rare or obsolete).^[10]
• 1840 – a silver compound suspended in collodion or gelatin, for coating photographic plates.^[2][7]
• 1930s – a paint.^[6] The Shorter Oxford dates this sense to the mid 20th century.^[10]

Meanings

Noun

1. A mixture of two liquids that do not fully combine, one of them dispersed through the other in tiny droplets.^[4][11][10]
2. (photography) A light-sensitive coating on film or paper, made of fine grains of a silver compound suspended in gelatin.^[11][2][4]
3. emulsion paint: a paint whose pigment is held in a resin dispersed in water, usually with a matt finish.^[11][10]
4. (pharmacology) A medicine in which an oily substance is dispersed in another liquid.^[11][2]
5. A milky liquid made by crushing almonds or other seeds in water.^[4][2][12]

Verb

1. To paint with emulsion paint.^[10]

Word family

• emulsive
• emulsible
• emulsify
• emulsoid

Related words

• emulsifier
• milk
• emulgent

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
6. ^ a b c d e Ayto, John (2005), Word Origins: The Secret Histories of English Words from A to Z, 2nd ed., London: A & C Black
7. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
9. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
10. ^ a b c d e f g h Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
11. ^ a b c d e Collins English Dictionary (2023), Glasgow: HarperCollins
12. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
13. ^ a b Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
14. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.