What is the meaning of Tenacity?

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

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

The effect of this attraction, cohesiveness.

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

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.

Source: wiktionary.org