Specifies how quickly a liquid spreads relative to its mass if it is poured out on a flat surface.
Are proportionality factor for the force it takes to parallel displace a surface relative to another, if the gap between these surfaces is filled with a viscous liquid or gas.
Density or volume mass is a SI unit and is a measure of the density of a specific substance, ie mass per unit volume. A synonym for density that can sometimes occur is specific importance.