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

Other reasons to seek additional care can include continued irritation, watering, burning, eye pain, mucus discharge, sensitivity to light, reduced vision and any flaking, discharge or sores on the eye or eyelid. —Hannah Yasharoff, USA Today, 29 Sep. 2025

Newborns and frail older people often have a hard time coughing up the mucus, Hopkins says. —Liz Szabo, Scientific American, 23 Sep. 2025

Meningococcal disease, per Cleveland Clinic, is a bacterial infection that can be spread through spit or mucus. —Raven Brunner, PEOPLE, 21 Sep. 2025

The mucus and cilia that normally trap larger dust cannot catch it. —Bill Frist, Forbes.com, 18 Sep. 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