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

These include having recurrent lung infections like acute bronchitis or pneumonia, new or worse shortness of breath, a cough that brings up mucus and phlegm, wheezing, chest tightness and fatigue. —Katia Hetter, CNN Money, 28 Aug. 2025

These messengers can cause muscles in the airways and gut to contract, increase mucus production and boost inflammation. —Hannah Millington, MSNBC Newsweek, 28 Aug. 2025

The sheer amount of toilet humor — there’s a lot of mucus, snot, and jokes about people drinking piss stuffed into one film — often proves more annoying than fun. —Wilson Chapman, IndieWire, 22 Aug. 2025

Typical symptoms include a chronic cough with mucus containing blood, plus fever, night sweats and weight loss. —Noah Lyons, Mercury News, 22 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