viscous

American  

[vis-kuhs] / ˈvɪs kəs /

adjective

1. of a glutinous nature or consistency; sticky; thick; adhesive.

2. having the property of viscosity.

---

viscous British  

/ ˈvɪskəs /

adjective

1. (of liquids) thick and sticky; viscid

2. having or involving viscosity

---

viscous Scientific  

/ vĭs′kəs /

1. Having relatively high resistance to flow (high viscosity).

---

Other Word Forms

• hyperviscous adjective
• pseudoviscous adjective
• viscously adverb
• viscousness noun

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.

Example Sentences

"It will also be interesting to see how this finding may be applied to assist fiber spinning and other applications that use viscous liquids."

From Science Daily • Mar. 30, 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

Under that scenario, the corresponding price tag on the heavy, viscous crude pumped in Venezuela would be in the high-$30s range.

From The Wall Street Journal • Jan. 20, 2026

“This is my witches’ brew,” she said laughing as she stirred the viscous inky liquid inside the bucket.

From Los Angeles Times • Jan. 8, 2026

I stooped over and picked it up in order to inspect the empty tin cylinder for a communication of some sort, but only a viscous residue of concentrated juice trickled out on my hand.

From "A Confederacy of Dunces" by John Kennedy Toole

Related Words

• gooey
• slimy
• syrupy