noun

viscosity

vih-SKAH-suh-tee/vɪˈskɑːsəti/

A fluid's resistance to flowing.

Honey's high viscosity makes it flow more slowly than water.

Two identical tipped glass vessels pour at the same angle: water streams freely from one, while thick honey descends sluggishly from the other, a clear visual comparison of resistance to flow.

Etymology

viscLatinmistletoe; birdlime

+osLatinfull of

+ityLatinstate or quality

The birdlime root first yields “sticky,” then the quality of being sticky or slow-flowing. In physics, viscosity gives that everyday image a precise meaning: internal friction that resists flow.

In context

Mathematics Aberystwyth13:07

a liquid but it is a liquid with a very high viscosity at low stresses so that it will flow very very slowly

INNFM: Yield Stress

More examples

Heating the oil lowers its viscosity.
The sauce needs enough viscosity to coat the noodles.
The lab compares the viscosities of several engine oils.

Forms

viscosity · viscosities

viscous adjective — Thick and resistant to flowing.

Similar words

thickness: Describes how thick a fluid seems, often less precisely.
consistency: Describes a substance's overall texture, not just flow resistance.