Main Entry: vis·cos·i·ty

Pronunciation: \vis-ˈkäs-ət-ē\

Function: noun

Inflected Form(s): plural vis·cos·i·ties

1 : the quality of being viscous ; especially : the property of resistance to flow in a fluid or semifluid
2 : the 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