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

As water evaporated, the juice was ladled from vat to vat, progressively reducing until a thick, viscous syrup remained. —Literary Hub, 29 July 2025

Soko’s innovative Hydrogel technology, used for denim finishing, transforms water into a highly viscous state, enveloping fabrics and protecting them from aggressive agents while reducing water consumption by up to 10 times compared to traditional methods. —Andrea Onate, Footwear News, 1 July 2025

For fans of the latter, Chablis is an ultimate pairing due to its medium body that stands up to the viscous butter with a flinty finish that accentuates the lobster’s salinity. —Jillian Dara, Forbes.com, 19 July 2025

Mollusk mucus is known to be five times more viscous than water. —ArsTechnica, 28 June 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