au da cious: -adjective 1. extremely bold or daring; recklessly brave; fearless: an audacious explorer. 2. extremely original; without restriction to prior ideas; highly inventive: an audacious vision of the city's bright future. 3. recklessly bold in defiance of convention, propriety, law, or the like; insolent; brazen. 4. lively; unrestrained; uninhibited: an audacious interpretation of her role.