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

The bourbon is oily and viscous, with a noticeable palate weight showcasing orange zest, cherry syrup, caramel, vanilla, and seasoned oak. —Joseph V Micallef, Forbes.com, 10 May 2025

Hoisin is sticky-sweet and soy-based, slightly viscous and very savory. —Kendra Vaculin, Bon Appétit, 21 Feb. 2025

The viscous substance coats the attacker, immobilizing or fatally compromising them by clogging joints, mouthparts and spiracles. —Scott Travers, Forbes.com, 5 Apr. 2025

The microbes go on to form a viscous coating known as a biofilm, which is resistant to antibiotics. —New Atlas, 28 Mar. 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