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 of viscous

• thick
• sticky

Examples of viscous in a Sentence

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

Recent Examples on the Web

The texture is robust and viscous. — Joseph V Micallef, Forbes.com, 28 May 2026

Cormorants that tried to clean each other with their beaks died after ingesting the viscous muck. — Jeffrey Marlow, New Yorker, 5 Apr. 2026

From having the viscous juices of decomposed leaves that kept her plump leak through a tear in her side, as happened to a few of her siblings. — María Ospina, The Dial, 31 Mar. 2026

That, the researchers surmise, is driving a general eastward flow of material through the viscous mantle. — ArsTechnica, 10 Apr. 2026

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
• 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