(n.) Unreasonable recklessness; extreme venturesomeness; rashness; as, the temerity of a commander in war\.

assurance audacity brashness brass brazen boldness cheek chutzpah daring foolhardiness gall hardihood hardiness heedlessness heroics hubris impertinence impetuosity improvidence imprudence impudence indiscretion injudiciousness insolence intrusiveness nerve overboldness overcarelessness overconfidence oversureness overweeningness precipitateness rashness recklessness temerariousness unchariness unwariness venturesomeness