Te‐nac″i‐ty (?), n. [L. tenacitas: cf. F. ténacité. See Tenacious.] 1. The quality or state of being tenacious; as, tenacity, or retentiveness, of memory; tenacity, or persistency, of purpose.
2. That quality of bodies which keeps them from parting without considerable force; cohesiveness; the effect of attraction; — as distinguished from brittleness, fragility, mobility, etc.
3. That quality of bodies which makes them adhere to other bodies; adhesiveness; viscosity. Holland.
4. (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.