vis·​cos·​i·​ty | \ vi-ˈskä-sə-tē How to pronounce viscosity (audio) \
plural viscosities

Definition of viscosity

1 : the quality or state of being viscous : a sticky or glutinous consistency
2a 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

Examples of viscosity in a Sentence

conducted an experiment to determine the viscosity of motor oil
Recent Examples on the Web Not all the synthetics here will be available in the viscosity recommended by your car's manufacturer. Gary Witzenburg, Car and Driver, 5 May 2022 Artificially Maple Flavored Syrup, which was the same color and viscosity as Dawn dish liquid. Hallie Lieberman, Smithsonian Magazine, 18 Apr. 2022 It’s just like how a fluid equation has a viscosity term to capture the net effect of short-distance molecular collisions. Quanta Magazine, 1 Mar. 2022 Just the pressure of his touch modeled the paint’s viscosity, affecting how light reflected off the surface. Brian T. Allen, National Review, 19 Mar. 2022 The hydrodynamic equation includes a term representing water’s viscosity — a single number, which can be measured at IR scales, that summarizes all those molecular interactions happening in the UV. Quanta Magazine, 1 Mar. 2022 However, the viscosity (how sticky a fluid is) of the water damps the instability. Chris Lee, Ars Technica, 31 Jan. 2022 The lower viscosity of the bioink permits the different layers to seep into one another, removing the need for rigidly pre-defined layers and, instead, creating a natural gradient. William A. Haseltine, Forbes, 4 Jan. 2022 There was more viscosity and body to this spirit, which gave it an almost syrup-like quality. Stephanie Breijo, Los Angeles Times, 2 Jan. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'viscosity.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of viscosity

14th century, in the meaning defined at sense 1

History and Etymology for viscosity

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

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Time Traveler for viscosity

Time Traveler

The first known use of viscosity was in the 14th century

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Dictionary Entries Near viscosity



viscosity breaking

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Statistics for viscosity

Last Updated

14 May 2022

Cite this Entry

“Viscosity.” Dictionary, Merriam-Webster, Accessed 22 May. 2022.

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More Definitions for viscosity


vis·​cos·​i·​ty | \ vis-ˈkäs-ət-ē How to pronounce viscosity (audio) \
plural viscosities

Medical Definition of viscosity

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

More from Merriam-Webster on viscosity

Nglish: Translation of viscosity for Spanish Speakers

Britannica English: Translation of viscosity for Arabic Speakers Encyclopedia article about viscosity


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