Kinematic viscosity is a measure of a fluid's resistance to flow under gravity, independent of its density. It is defined as the ratio of the dynamic viscosity of a fluid to its density, and is typically measured in units of square meters per second (m²/s) or centistokes (cSt).

Kinematic viscosity is an important property of fluids in many industrial and scientific applications. It is used to describe the flow behavior of liquids and gases in pipes, channels, and other flow systems. Kinematic viscosity is also an important parameter in the design of engines and other machinery that rely on the movement of fluids, as it affects the efficiency and performance of these systems.

The kinematic viscosity of a fluid depends on its temperature and pressure, as well as its chemical composition and physical properties such as molecular weight and size. It is typically measured using a viscometer, which measures the time it takes for a small volume of fluid to flow through a capillary tube under the influence of gravity.