temerity
n. US //təˈmɛɹəti// UK //tɛmˈɛɹɪti// temer·i·ty
From Middle English temerite, temeryte, from Old French temerité, from Latin temeritās (“chance, accident, rashness”), from temere (“by chance, casually, rashly”). By surface analysis, temer(arious) + -ity.