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

Examination revealed bradycardia, i.e., a slow heart rate, a blue tinge to the dog's mucus membranes—often a sign of too much unoxygenated hemoglobin circulating through the system—and dilated pupils. —Jennifer Ouellette, ArsTechnica, 18 Aug. 2025

The agency also warns that saliva contact from a bat to a human’s mucus membrane or other physical contact with a bat can be considered a risk for rabies exposure. —Owen Clarke, Outside, 14 Aug. 2025

As a result, thick mucus builds up in the lungs and traps bacteria, causing infections and inflammation. —Dhruv Khullar, New Yorker, 11 Aug. 2025

But mucus serves many healthful roles, primarily as a medium for catching and removing harmful particles and pathogens from the body. —Scott Lafee, San Diego Union-Tribune, 5 Aug. 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