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

Staying hydrated thins mucus naturally, and sleeping with your head slightly elevated encourages drainage. —Daryl Austin, USA Today, 19 Nov. 2025

But the ghost pepper sauce (people use it on pizza and barbecue) is a whole lot livelier, hitting both of us in the back of our throats, and in my case, turning on the mucus train. —Kansas City Star, 18 Nov. 2025

Insoluble fiber mildly irritates the intestinal lining, stimulating the secretion of water and mucus, which encourages the movement of stool. —Heather Jones, Verywell Health, 14 Nov. 2025

The virus spreads through an animal’s saliva, mucus and feces, or through milk from dairy cattle. —Jen Christensen, CNN Money, 14 Nov. 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