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

Direct contact with mpox rash or scabs as well as contaminated bodily fluids — like mucus, salivia or blood — are the most common ways people pass the virus to each other. —Mary Walrath-Holdridge, USA Today, 17 Oct. 2025

The disease causes an overabundance of mucus, trapping infections and blocking airways in the lungs. —Katie Hunt, CNN Money, 4 Oct. 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

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