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

Bacteria and other small creatures squirming inside bodies often have to propel themselves through thick, viscous environments. —Mack Degeurin, Popular Science, 9 Oct. 2024

For cells, living in a cold and more viscous fluid means getting less to eat. —Veronique Greenwood, WIRED, 11 Aug. 2024

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

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