Noun

1. The quality or state of being tenacious; as, tenacity, or retentiveness, of memory; tenacity, or persistency, of purpose.
   • 2009, Jorge Cham, PHD Comics: Softball: younger and faster

     — Our opponents may be younger, faster and less out of shape than we are, but we have something they’ll never have!

     — Tenure?

     — Tenacity!

2. The quality of bodies which keeps them from parting without considerable force; cohesiveness; the effect of attraction; – as distinguished from brittleness, fragility, mobility, etc.
3. The quality of bodies which makes them adhere to other bodies; adhesiveness; viscosity.
4. 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.