mucus

Etymology

It is borrowed from Latin mūcus (“nasal mucus, snot”), also spelled muccus.^{[2][3][4][5][6]} The Latin noun is related to ēmungō (“to blow the nose”) and mūceō (“to be mouldy or musty”),^[4][3][7] and is cognate with Ancient Greek μύξα (múxa, “slime, mucus”), μύσσεσθαι (mússesthai, “to blow the nose”) and μυκτήρ (muktḗr, “nose, nostril”).^[2][5][8] Etymonline traces it to Proto-Indo-European *meug- (“slippery, slimy”),^[3] and Barnhart adds the cognates Welsh mign (“swamp”) and Old Norse mykr (“cow dung”).^[4] The adjective mucous is from mūcōsus (“slimy”).^[8][4]

Earliest recorded meaning

The slimy substance secreted by the membranes of the body: 1597, in Gabriel Harvey's Trimming of Thomas Nashe.^[2] Merriam-Webster gives the same year,^[9] while Barnhart dates the word to 1661 and Etymonline to the 1660s.^[4][3]

Semantic evolution

In Latin the word meant above all the mucus of the nose.^[2][5][8] In English it replaced the earlier term mucilage, used in Middle English from 1392 for the same substance.^[4][3] Johnson (1755) defined it first as the fluid that flows into the nostrils, and then as any slimy moisture that lines the bowels and passages of the body.^[10] From 1788 it was also used in botany for plant mucilage, after French muqueux, a sense now rare.^[2]

Timeline

• 1597 – a viscous secretion of the mucous membranes.^[2][9] Barnhart dates the word to 1661.^[4]
• 1755 – Johnson defines it as the fluid of the nostrils and any slimy moisture of the body.^[10]
• 1788 – in botany, plant mucilage (now rare).^[2]

Meanings

Noun

1. A thick, slippery secretion produced by the mucous membranes, which moistens and protects them: A cold fills the nose with mucus.^[11][9][2]
2. A similar slimy secretion of other animals, such as the trail of a snail.^[9]
3. (botany, rare) Plant mucilage.^[2]

Word family

• mucoid

Related words

• mucilaginous
• mucosa
• mucous
• mucilage
• moist
• muck

References

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