The difference between Tenacity and Viscosity

Tenacity as a noun:

The quality or state of being tenacious, or persistence of purpose; tenaciousness.

Tenacity as a noun:

The quality of bodies which keeps them from parting without considerable force, as distinguished from brittleness, fragility, mobility, etc.

Tenacity as a noun:

The effect of this attraction, cohesiveness.

Tenacity as a noun:

The quality of bodies which makes them adhere to other bodies; adhesiveness, viscosity.

Tenacity as a noun (physics):

The greatest longitudinal stress a substance can bear without tearing asunder, usually expressed with reference to a unit area of the cross section of the substance, as the number of pounds per square inch, or kilograms per square centimeter, necessary to produce rupture.

Viscosity as a noun (uncountable):

The state of being viscous.

Viscosity as a noun (countable, physics):

A quantity expressing the magnitude of internal friction in a fluid, as measured by the force per unit area resisting uniform flow.

Viscosity as a noun (uncountable, psychology):

A tendency to prolong interpersonal encounters.