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

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

There's a protective mucus that the snails use to seal themselves inside their shells in the winter. — Ari Daniel, NPR, 6 Aug. 2026

Your Mucus Changes Changes in mucus (phlegm) are among the most common signs of a COPD flare-up. — Md Published, Verywell Health, 6 Aug. 2026

Until a decade ago, scientists thought of these cilia merely as brooms that move mucus and sweep away waste particles and other debris. — Marlowe Starling, Quanta Magazine, 5 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