Definition of viscosity
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
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
