te·nac·i·ty (tə-nās'ĭ-tē) n. The state or quality of being tenacious: "Social styles developed in the 19th century withstand, with sporelike tenacity, all that the present century can throw at them"(Larry McMurty).
1526, from M.Fr. ténacité (14c.), from L. tenacitas "the act of holding fast," from tenax (gen. tenacis) "tough, holding fast," from tenere "to hold" (see tenet). Tenacious first attested 1607.