noun

viscosity

/vɪˈskɒsɪti/ · say it: vis·KAH·suh·tee

a fluid's resistance to flowing

In Science & Nature

In more detail

1. (noun) the thickness of a liquid and how much it resists flowing

2. (noun) the quality or state of being thick and sticky

Examples

1. Honey has high viscosity, so it flows slowly compared to water.
2. The viscosity of the oil increased as the temperature dropped.

How to use viscosity

Viscosity is primarily a technical and scientific term used in physics, chemistry, and engineering to quantify resistance to flow in liquids and gases. It is commonly used to describe the behavior of oils, molasses, and other thick substances, and is measured in specific units (poises, pascals). While not everyday vocabulary, it can also be used more colloquially to describe the general thickness or stickiness of any liquid.

Common phrases

high viscosity
low viscosity
increase viscosity
viscosity index
viscosity of oil

Synonyms

thickness · stiffness · density · sluggishness

Opposites

fluidity · thinness

Word family

viscous (adjective) · viscously (adverb)

A common mistake

Learners sometimes confuse viscosity with density, which are distinct properties; a liquid can have high viscosity but low density, or vice versa.

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