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

Clearing one’s throat is a common reflex to remove mucus and irritants — particularly during allergy season. —Khloe Quill, FOXNews.com, 6 Apr. 2025

The bacteria attach to tiny, hairlike structures in the lungs called cilia, which help sweep the lungs clear of mucus and irritants. —Tanya Lewis, Scientific American, 4 Apr. 2025

Lifestyle Changes Staying hydrated throughout the day can help thin nasal mucus and make breathing easier. —Lindsay Curtis, Health, 5 Mar. 2025

The pope inhaled a significant amount of mucus, marking another setback in his ongoing two-week struggle with a complex respiratory infection and pneumonia. —Gordon G. Chang, Newsweek, 3 Mar. 2025

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
• verrucous

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