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

Measles shows up in wastewater because infected people naturally shed tiny bits of the virus in things like mucus, saliva and stool. —Evan Moore, Charlotte Observer, 13 Jan. 2026

The theory that dairy increases mucus production has not been proven. —Cristina Mutchler, Verywell Health, 13 Jan. 2026

The ingredient, a glycoprotein found in these mollusks’ sticky mucus, has become a popular addition to skincare products over the years. —Hunter Boyce, AJC.com, 13 Jan. 2026

Given the lack of gravity, even a runny nose can turn into an extremely unpleasant experience, forcing astronauts to resort to unusual measures just to drain mucus from their nasal passages. —Victor Tangermann, Futurism, 8 Jan. 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
• 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