n. [ Cf. F. viscosité, LL. viscositas. ] 1. The quality or state of being viscous. [ 1913 Webster ]
2. (Physics) A property possessed by a viscous fluid, being a resistance to the forces causing a fluid to flow, caused by interactions between the molecules of the fluid and between the fluid and the walls of the conduit through which it moves; also, a measure of such a property. [ 1913 Webster +PJC ]