"To boldly go where no man has gone before"
Boldness, brazenness, or audacity was the willingness to get something done with disregard for the risks involved.
According to the Xindi-Primate Degra, the Xindi-Aquatics "respect boldness and confidence." (ENT: "The Council")
In a speech given by Zephram Cochrane at the dedication of the Warp 5 Complex during the early 22nd century, "This engine will let us go boldly where no man has gone before." A playback of the speech was later broadcast at the launch of the Enterprise NX-01. (ENT: "Broken Bow") Three years later, following the Xindi incident and prior to the launch of the Enterprise's sister ship Columbia, Captain Jonathan Archer cynically noted to Columbia Captain Hernandez, "Things have changed since Enterprise left Spacedock. You'll spend a lot of your time boldly going into battle." (ENT: "Home")
A plaque aboard the USS Enterprise-A later stated the similar saying: "To boldly go where no man has gone before". Captain James T. Kirk placed his hand on the plaque as the ship approached Sha Ka Ree in 2287. (Star Trek V: The Final Frontier) Nearly a decade later, in 2293, Kirk noted in his final log entry that "This is the final cruise of the starship Enterprise under my command. This ship and her history will shortly become the care of another crew. To them and their posterity will we commit our future. They will continue the voyages we have begun and journey to all the undiscovered countries, boldly going where no man, where no one, ...has gone before." (Star Trek VI: The Undiscovered Country)
According to the Ligonian code of honor, which was used to test the crew of the USS Enterprise-D in 2364, during their first step towards establishing a treaty between themselves and the Federation, was for their leader, Lutan, to kidnap Tasha Yar to "achieve recognition for being daring and bold." In such an event, the proper thing was for the leader of the opposing party was "to ask to get Tasha back– politely." (TNG: "Code of Honor")
In 2365, Commander William T. Riker had the audacity to challenge Sirna Kolrami to a game of Strategema. (TNG: "Peak Performance")
According to Edward Jellico, "Cardassians are like timber wolves, predators, bold in large numbers". (TNG: "Chain Of Command, Part I")