vis·​cous ˈvi-skəs How to pronounce viscous (audio)
: having a thick or sticky consistency : viscid
viscous secretions
viscous corn syrup
technical : having or characterized by a high resistance to flow
viscous lava
viscously adverb
viscousness noun

Examples of viscous in a Sentence

viscous syrup that takes forever to pour from a narrow-neck bottle
Recent Examples on the Web One of those benchmarks is a simulated swimmer: a three-link body resting on the ground in a viscous environment that needs to learn to swim as fast as possible in a certain direction. Jacek Krywko, Ars Technica, 10 May 2024 The air is clogged with cigarette smoke and marijuana smoke and tension as viscous as Marmite. Sara Holdren, Vulture, 20 Apr. 2024 Humans navigate this environment without noticing much resistance, but silk fibers are buffeted about by the velocity of the viscous forces in air. Jordan Pearson, New York Times, 16 May 2024 The extruder melted thousands of tiny black pellets into a viscous goo. August Brown, Los Angeles Times, 23 May 2024 See all Example Sentences for viscous 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'viscous.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Middle English viscouse, from Anglo-French viscos, from Late Latin viscosus full of birdlime, viscous, from Latin viscum mistletoe, birdlime; akin to Old High German wīhsila cherry, Greek ixos mistletoe

First Known Use

14th century, in the meaning defined at sense 1

Time Traveler
The first known use of viscous was in the 14th century

Dictionary Entries Near viscous

Cite this Entry

“Viscous.” Dictionary, Merriam-Webster, Accessed 14 Jul. 2024.

Kids Definition


vis·​cous ˈvis-kəs How to pronounce viscous (audio)
: having the characteristic of stickiness
: having or marked by viscosity

Medical Definition


vis·​cous ˈvis-kəs How to pronounce viscous (audio)
: having a glutinous consistency and the quality of sticking or adhering : viscid
: having or characterized by viscosity
a viscous flow

More from Merriam-Webster on viscous

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!