mucus

noun

mu·​cus ˈmyü-kəs 

: 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

Recent Examples on the Web

AstraZeneca's drug works by blocking a protein called IL-33 that drives inflammation and mucus production, two of the underlying disease drivers of COPD. — Annika Kim Constantino, CNBC, 8 Sep. 2026

Bowel movements should also be relatively consistent and free of blood, mucus or foreign material. — Lauren Paige Richeson, USA Today, 19 Aug. 2026

Type of Diarrhea With salmonella poisoning, diarrhea can contain blood or mucus. — Tom Gavin, EverydayHealth.com, 11 Aug. 2026

The researchers analyzed all five types of mucus using various techniques, including proteomics, X-ray fluorescence, X-ray diffraction, cryoscanning electron microscopy, and liquid chromatography. — Jennifer Ouellette, ArsTechnica, 7 Aug. 2026

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

Rhymes for mucus

• fucus
• mucous
• caducous
• sambucus
• submucous

Kids Definition

mucus

noun

mu·​cus ˈmyü-kəs 

: a slippery sticky substance produced especially by mucous membranes which it moistens and protects

Medical Definition

mucus

noun

mu·​cus ˈmyü-kəs 

: a viscid slippery secretion that is usually rich in mucins and is produced by mucous membranes which it moistens and protects