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

• thick
• sticky
• syrupy

Examples of viscous in a Sentence

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

Recent Examples on the Web

The red smile in her neck pulses viscous filling down her chest, over the four letters on the plastic name badge pinned to her shirt. —Carly Tagen-Dye, People.com, 30 June 2025

Shake your ingredients for 15-20 seconds (or longer for more viscous ingredients) before straining the drink into a chilled glass. —Bestreviews, Chicago Tribune, 24 June 2025

Five unique whiskeys blended into a viscous, golden liquid . . . —Jonah Flicker, Robb Report, 23 June 2025

The researchers focused particularly on the proteins found in synovial fluid in healthy and injured knee joints, that is, the viscous liquid found in joint spaces that lubricates the cartilage and helps reduce friction during movement. —Paul McClure 31, New Atlas, 31 May 2025

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

Rhymes for viscous

• discus
• viscus
• hibiscus
• meniscus

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