temerity
Meaning: audacity, recklessness
Usage: Tom and Huck entered the scary cave armed with nothing but their own temerity.
effrontery
Meaning: impudence, nerve, insolence
Usage: When I told my aunt that she was boring, my mother scolded me for my effrontery.
audacious
Meaning: excessively bold
Usage: The security guard was shocked by the fan’s audacious attempt to offer him a bribe.
brazen
Meaning: excessively bold, brash
Usage: Critics condemned the novelist’s brazen attempt to plagiarize Hemingway’s story.
presumptuous
Meaning: disrespectfully bold
Usage: It was presumptuous of Liam to submit the group’s project before asking his teammates.