mu·​cus | \ ˈmyü-kəs \

Definition of mucus 

: 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 triggers provoke inflammation, constriction, and excessive mucus production in a person’s airways, which can lead to symptoms like shortness of breath, coughing, chest pain, and wheezing (an alarming whistling sound during breathing). Korin Miller, SELF, "7 People Describe What an Asthma Attack Actually Feels Like," 14 Nov. 2018 But each of us carries a miniature chemistry lab deep inside our nose, in the form of sensing cells coated in a thin layer of mucus. Helen Czerski, WSJ, "Wintry Scents, Indoors and Out," 20 Dec. 2018 The molecules stick to a layer of mucus on the upper surface of the cavity, embedded with olfactory neurons. Tim Folger, Discover Magazine, "How Quantum Mechanics Lets Us See, Smell and Touch," 24 Oct. 2018 Cystic fibrosis is caused by a genetic defect that allows a buildup of thick mucus in the lungs, and other internal organs. Bradley J. Fikes,, "Vertex Pharmaceuticals opens expanded San Diego research center with focus on cystic fibrosis," 18 June 2018 The moisture in the respiratory tract and mucus membranes makes these areas especially sensitive to these agents. Korin Miller, SELF, "This Is Exactly How Tear Gas Affects Your Body," 26 Nov. 2018 One common reason ears just won't pop? Colds or allergies, which cause your mucus membranes to become inflamed. Brian Sumers, Condé Nast Traveler, "How to Pop Your Ears on a Plane—And Why They Pop, Anyway," 10 Sep. 2018 The update also began letting users log other female health data like cervical mucus quality and basal body temperature. Julie Bogen, The Verge, "How period tracking apps helped me regain control after going off the pill," 23 Sep. 2018 These cells produce a basic mucus that neutralizes the acid in your stomach. Megan Arnett, Scientific American, "Sweet and Sour Science You Can Taste!," 21 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mucus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of mucus

1597, in the meaning defined above

History and Etymology for mucus

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" myxo-

Note: See note at myxo-.

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Statistics for mucus

Last Updated

10 Jan 2019

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Time Traveler for mucus

The first known use of mucus was in 1597

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English Language Learners Definition of mucus

: a thick liquid that is produced in some parts of the body (such as the nose and throat)


mu·​cus | \ ˈmyü-kəs \

Kids Definition of mucus

: a slippery thick sticky substance that coats, protects, and moistens the linings of body passages and spaces (as of the nose, lungs, and intestines)


mu·​cus | \ ˈmyü-kəs \

Medical Definition of mucus 

: a viscid slippery secretion that is usually rich in mucins and is produced by mucous membranes which it moistens and protects

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More from Merriam-Webster on mucus

Spanish Central: Translation of mucus

Nglish: Translation of mucus for Spanish Speakers

Britannica English: Translation of mucus for Arabic Speakers Encyclopedia article about mucus

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