viscosity

American  

[vi-skos-i-tee] / vɪˈskɒs ɪ ti /

noun

• viscosities
  plural

1. the state or quality of being viscous.

2. Physics.

   1. the property of a fluid that resists the force tending to cause the fluid to flow.

   2. the measure of the extent to which a fluid possesses this property.

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viscosity British  

/ vɪsˈkɒsɪtɪ /

noun

1. the state or property of being viscous

2. physics

   1. the extent to which a fluid resists a tendency to flow

   2.  η.  Also called: absolute viscosity.  a measure of this resistance, equal to the tangential stress on a liquid undergoing streamline flow divided by its velocity gradient. It is measured in newton seconds per metre squared See also kinematic viscosity specific viscosity

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viscosity Scientific  

/ vĭ-skŏs′ĭ-tē /

1. The resistance of a substance to flow. For example, water has a lower viscosity than molasses and flows more easily. Viscosity is related to the concept of shear force; it can be understood as the effect of different layers of the fluid exerting shearing force on each other, or on other surfaces, as they move against each other. Viscosity lies behind the skin friction component of drag.

2. ◆ Kinematic viscosity is a measure of the rate at which momentum is transferred through a fluid. It is measured in stokes.

3. ◆ Dynamic viscosity is a measure of the ratio of the stress on a region of a fluid to the rate of change of strain it undergoes. It is equal to the kinematic viscosity times the density of the fluid. It is measured in pascal-seconds or poises.

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viscosity Cultural  

1. The internal friction of a fluid, produced by the movement of its molecules against each other. Viscosity causes the fluid to resist flowing.

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Other Word Forms

Derived Forms

• hyperviscosity
  noun

Inflected Forms

Nouns

• viscosities
  plural

Etymology

Origin of viscosity

First recorded in 1375–1425; late Middle English, from Medieval Latin viscōsitās, from Latin viscōs(us) viscous + -itās -ity

Explanation

Viscosity is the thickness of a liquid. Water flows easily. Honey does not — that's why it has greater viscosity than water. Viscosity, pronounced "vis-KOSS-ih-tee," tells you how sticky a liquid is. In the working of machines and car engines, viscosity is important. Thick oils and lubricants that have high viscosity, meaning they coat and cling, keep hard metal parts from wearing down as they rub together. Oils with dense viscosity keep machine parts from having too much friction and burning out.

Example Sentences

See Examples For:

viscosity viscosities

The goal is to find the perfect viscosity of chocolate on Magnum bars, for the perfect crunch.

From BBC ● Aug. 14, 2026

Soon, this liquid ferments into a tangy beverage with a touch of viscosity, somewhat like Mexico’s pulque.

From Los Angeles Times ● Jun. 24, 2026

Other researchers have also examined how viscosity itself may arise from deeper physical laws.

From Science Daily ● May 8, 2026

The team also measured how easily this fluid flows and found that its viscosity is extremely low, making it one of the closest realizations of a perfect fluid ever observed.

From Science Daily ● Apr. 15, 2026

She seems unaffected by the newfound viscosity in the air.

From "Kwame Crashes the Underworld" by Craig Kofi Farmer

At lower viscosities, the liquids could not be broken because the testing equipment could not stretch them fast enough.

From Science Daily ● Mar. 30, 2026

The team then tested the stability of the lava under a range of speeds, viscosities, and layer thicknesses.

From Science Magazine ● Jun. 9, 2023

Honey, syrup, motor oil, and other liquids that do not flow freely, like those shown in Figure 10.15, have higher viscosities.

From Textbooks ● Feb. 14, 2019

Break it in two at room temperature and its various layers will stretch and ooze at different delicious viscosities.

From Washington Post ● Jan. 3, 2018

By diluting the new "maximum viscosity" solution, therefore, with the 10 per cent. solution of the gum arabic in fixed proportions we obtain a series of viscosities which are shown in the following curve.

From Scientific American Supplement, No. 821, September 26, 1891 by Various