viscous
Americanadjective
-
of a glutinous nature or consistency; sticky; thick; adhesive.
-
having the property of viscosity.
adjective
-
(of liquids) thick and sticky; viscid
-
having or involving viscosity
Other Word Forms
Derived Forms
Etymology
Origin of viscous
1350–1400; Middle English < Late Latin viscōsus, equivalent to Latin visc ( um ) mistletoe, birdlime (made with mistletoe berries) + -ōsus -ous
Explanation
Viscous means sticky, gluey and syrupy. So if something is viscous, you usually don't want to stick your fingers in it — that goes for boogers and maple syrup alike. Not quite a solid and not quite a liquid, scientists like to say that viscous things don't flow very easily. They glop and slug around slowly, sticking to whatever they come in contact with. Think of making a batch of Rice Krispie treats: One minute the marshmallows are solid little rounds; the next minute they're melted into a web of sticky white goo that's somehow attached itself to the Rice Krispies, the spoon, the countertops, your nose, the front door, and the dog.
Vocabulary lists containing viscous
The Vocabulary.com Top 1000
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Grade 11, List 6
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Stroke of Genius: Words About Painting
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The thought is that donating blood reduces iron levels and makes the blood less viscous; thicker blood is associated with a higher risk of blood clots and heart attacks.
From Slate • May 9, 2026
The study, published in Physical Review Letters, demonstrates that viscous liquids can abruptly snap when stretched with enough force.
From Science Daily • Mar. 30, 2026
American fuel makers are snapping up the rising supplies of Venezuela’s heavy, viscous oil that their refineries were designed to process.
From The Wall Street Journal • Mar. 5, 2026
A resurgence of Venezuela's industry could pose problems for Canada, which produces similarly viscous oil and exports much of it to the US, but analysts reckon the risk is minor.
From BBC • Feb. 15, 2026
Clouds of dark viscous fluid - poison, perhaps - curled from his blue skin.
From "Blood of Olympus" by Rick Riordan
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
