Origin of temerariousClassical Latin temerarius ; from temere: see temerity
Presumptuously or recklessly bold; rash or reckless: “I would never have been temerarious enough to make use of such a title on my own” (Brendan Gill). See Synonyms at reckless.
Origin of temerariousFrom Latin temerarius, from temere, rashly.
From Latin temerÄrius (“that happens by chance, imprudent"), from temerÄ“ (“by chance, at random, rashly").