Webster's Revised Unabridged Dictionary · 1913

Temerity

Temerity , noun

[Latin temeritas, from temere by chance, rashly; perhaps akin to Sanskrit tamas darkness: compare French témérité.]

Unreasonable contempt of danger; extreme venturesomeness; rashness; as, the temerity of a commander in war.
It is notorious temerity to pass sentence upon grounds uncapable of evidence. — Barrow
Her rush hand in evil hour Forth reaching to the fruit, she plucked, she eat. — Milton