viscous

adjective

vis·​cous ˈvi-skəs 

1

: having a thick or sticky consistency : viscid

viscous secretions

viscous corn syrup

2

technical : having or characterized by a high resistance to flow

viscous lava

viscously adverb

viscousness noun

Synonyms

• ropy
• ropey
• syrupy
• thick
• viscid

Examples of viscous in a Sentence

viscous syrup that takes forever to pour from a narrow-neck bottle

Recent Examples on the Web

One way to visualize this is to imagine the Higgs boson as a thick, viscous soup that fills the universe. —Paul M. Sutter, Discover Magazine, 17 Sep. 2024

Why lava is so hard to stop Lava is a sluggish, viscous fluid that behaves somewhat like tar. —Loÿc Vanderkluysen, The Conversation, 17 Jan. 2024

Related Articles Map: Bear Fire evacuation and perimeter north of Tahoe Dong said the lab redesigned the new gel to be viscous — or runny — enough to be sprayed through traditional fire retardant hoses. —Tom Li, The Mercury News, 1 Sep. 2024

The team went back and observed viscous but not hardened hemolymph oozing from wounds. —Elizabeth Rayne, Ars Technica, 8 Apr. 2024

Word History

Etymology

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

Kids Definition

viscous

adjective

vis·​cous ˈvis-kəs 

1

: having the characteristic of stickiness

2

: having or marked by viscosity

Medical Definition

viscous

adjective

vis·​cous ˈvis-kəs 

1

: having a glutinous consistency and the quality of sticking or adhering : viscid

2

: having or characterized by viscosity

a viscous flow