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
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
This 30-year-old expression is smooth, flavorful, and rich on the palate, with an oily viscosity and full-bodied robustness that envelops the mouth.
—Joseph V Micallef, Forbes.com, 1 July 2025
In their modeling, La Spina and his colleagues found that tweaking the viscosity of magma erupting in a lava fountain can generate big changes.
—Erik Klemetti, Discover Magazine, 12 May 2025
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
See All Example Sentences for viscosity
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Joseph V Micallef, Forbes.com, 1 July 2025
In their modeling, La Spina and his colleagues found that tweaking the viscosity of magma erupting in a lava fountain can generate big changes.
—Erik Klemetti, Discover Magazine, 12 May 2025
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
See All Example Sentences for viscosity
Cite this Entry
“Viscosity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/viscosity. Accessed 22 Jul. 2025.
Copy CitationKids 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
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