[myoo-kuh s]


a viscous, slimy mixture of mucins, water, electrolytes, epithelial cells, and leukocytes that is secreted by glands lining the nasal, esophageal, and other body cavities and serves primarily to protect and lubricate surfaces.

Origin of mucus

1655–65; < Latin mūcus snot; akin to Greek myktḗr nose, mýxa slime
Can be confusedmucous mucus Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for mucus

sludge, mud, goo, gunk, mucus, saliva, bile, mire, scum, ooze, fungus, glop, gum, juice, sweat, sap, milk, tears

Examples from the Web for mucus

Contemporary Examples of mucus

Historical Examples of mucus

British Dictionary definitions for mucus



the slimy protective secretion of the mucous membranes, consisting mainly of mucin

Word Origin for mucus

C17: from Latin: nasal secretions; compare mungere to blow the nose; related to Greek muxa mucus, muktēr nose


See mucous
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for mucus

1660s (replacing Middle English mucilage), from Latin mucus "slime, mold, mucus of the nose, snot," from PIE root *meug- "slippery, slimy," with derivatives referring to wet or slimy substances or conditions (cf. Latin emungere "to sneeze out, blow one's nose," mucere "be moldy or musty," Greek myssesthai "to blow the nose," myxa "mucus," mykes "fungus," Sanskrit muncati "he releases"). Old English had horh, which may be imitative.

Online Etymology Dictionary, © 2010 Douglas Harper

mucus in Medicine




The viscous slippery substance that consists chiefly of mucin, water, cells, and inorganic salts and that is secreted as a protective lubricant coating by the cells and glands of the mucous membranes.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

mucus in Science



The slimy, viscous substance secreted as a protective lubricant by mucous membranes. Mucus is composed chiefly of large glycoproteins called mucins and inorganic salts suspended in water.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

mucus in Culture


A slippery and somewhat sticky fluid secreted by the glands in mucous membranes. Mucus lubricates and protects the mucous membranes.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.