viscosity

noun

vis·​cos·​i·​ty vi-ˈskä-sə-tē 

plural viscosities

1

: the quality or state of being viscous : a sticky or glutinous consistency

2

a

technical : the property of resistance to flow in any material with fluid properties

… water has a small but measurable viscosity, or "stickiness," which results from the weak mutual attraction of water molecules.

—Hans Christian von Baeyer

b

: the mathematical ratio of the tangential frictional force per unit area to the velocity gradient perpendicular to the direction of flow of a liquid

called also coefficient of viscosity

Synonyms

• consistency
• consistence
• thickness

Examples of viscosity in a Sentence

conducted an experiment to determine the viscosity of motor oil

Recent Examples on the Web

Its viscosity also helps visibly smooth ridges, splits, and discoloration. —Devon Abelman, Allure, 28 May 2025

Robinson emphasizes that peptide lip products are typically lower in viscosity compared to traditional balms, which have a thicker consistency. —Jessica Fields, Essence, 7 May 2025

Treating teatime like a wine tasting by noticing the tannins, flavor notes, and the viscosity of what’s in your cup is a great way to develop your palate. —Oset Babür-Winter, Bon Appetit Magazine, 1 May 2025

Despite its inherent maximalism—the visual complexity of piled-high ingredients of varying textures and colors and temperatures and viscosities—a sundae is the most emotionally simple of desserts, and the most honest. —Helen Rosner, New Yorker, 25 May 2025

Word History

Etymology

Middle English viscosite, from Anglo-French viscosité, from Medieval Latin viscositat-, viscositas, from Late Latin viscosus viscous

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing viscosity

• coefficient of viscosity
• viscosity index

Rhymes for viscosity

• atrocity
• ferocity
• monstrosity
• pomposity
• porosity
• precocity
• schistosity
• velocity
• verbosity
• animosity
• curiosity
• generosity

Kids Definition

viscosity

noun

vis·​cos·​i·​ty vis-ˈkäs-ət-ē 

plural viscosities

: the quality or state of being viscous

especially : the characteristic of a fluid that resists flow

an oil of high viscosity

Medical Definition

viscosity

noun

vis·​cos·​i·​ty vis-ˈkäs-ət-ē 

plural viscosities

1

: the quality of being viscous

especially : the property of resistance to flow in a fluid or semifluid

2

: the ratio of the tangential frictional force per unit area to the velocity gradient perpendicular to the direction of flow of a liquid

called also coefficient of viscosity