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

• consistence
• consistency
• density
• thickness
• viscidity

Examples of viscosity in a Sentence

conducted an experiment to determine the viscosity of motor oil

Recent Examples on the Web

The thickness of the slab and the viscosity (or gumminess) of this region of the mantle, Wang says, could explain the slow sinking speed. —Jeanna Bryner, Scientific American, 17 Oct. 2024

For dishes that are lightly soiled and don't contain food with a high viscosity, Vuong recommends soaking the dishes for 5-10 minutes in hot, soapy water. —Claire Hoppe, Better Homes & Gardens, 26 Sep. 2024

The viscosity lathers well without being overly foamy, and the essential oils provide antibacterial, antimicrobial, anti-inflammatory, and detoxifying benefits. —Michael Stefanov, Robb Report, 15 Aug. 2024

This natural component in the body has a host of jobs – from cushioning joints to helping sustain elasticity and viscosity of extracellular substances. —New Atlas, 31 July 2024

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

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