mucus

noun

mu·​cus ˈmyü-kəs How to pronounce mucus (audio)
: a viscid slippery secretion that is usually rich in mucins and is produced by mucous membranes which it moistens and protects

Examples of mucus in a Sentence

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Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The biologists reported that some had closed shut or spit out mucus to try to clear the mud. — Jenny Staletovich, Miami Herald, 30 July 2026 Salmonella infection, or salmonellosis, can cause nausea, vomiting, diarrhea that might have blood or mucus, abdominal cramps and fever. — Julie Gallant, San Diego Union-Tribune, 29 July 2026 Key Takeaways Early research suggests that aloe vera juice may support the gut lining by maintaining tight junctions, increasing mucus production, and reducing inflammation, but these effects have not been proven in humans. — Morgan Pearson, Verywell Health, 29 July 2026 Your eyes constantly produce a thin layer of basal tears to keep the cornea lubricated, and the duct quietly shuttles that trickle into the nose, where it’s absorbed or blended into normal nasal mucus without a trace. — Scott Travers, Forbes.com, 23 July 2026 See All Example Sentences for mucus

Word History

Etymology

borrowed from Latin mūcus, muccus "nasal discharge," perhaps going back to *moukos, o-grade derivative of Indo-European *(s)muk- "nasal discharge," *(s)meuk- "undo, loosen, wipe off" — more at myxo-

Note: See note at myxo-.

First Known Use

1597, in the meaning defined above

Time Traveler
The first known use of mucus was in 1597

Rhymes for mucus

See All Rhymes for mucus

Browse Nearby Words

muculent
mucus
mud
See all Nearby Words

Cite this Entry

“Mucus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mucus. Accessed 8 Aug. 2026.

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Kids Definition

mucus

noun
mu·​cus ˈmyü-kəs How to pronounce mucus (audio)
: a slippery sticky substance produced especially by mucous membranes which it moistens and protects

Medical Definition

mucus

noun
mu·​cus ˈmyü-kəs How to pronounce mucus (audio)
: a viscid slippery secretion that is usually rich in mucins and is produced by mucous membranes which it moistens and protects

More from Merriam-Webster on mucus

Nglish: Translation of mucus for Spanish Speakers

Britannica.com: Encyclopedia article about mucus

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