Source : Webster's Revised Unabridged Dictionary (1913)

Audacity \Au*dac"i*ty\, n.
   1. Daring spirit, resolution, or confidence; venturesomeness.

            The freedom and audacity necessary in the commerce
            of men.                               --Tatler.

   2. Reckless daring; presumptuous impudence; -- implying a
      contempt of law or moral restraints.

            With the most arrogant audacity.      --Joye.

Source : WordNet®

audacity
     n 1: fearless daring [syn: {audaciousness}, {temerity}]
     2: aggressive boldness or unmitigated effrontery; "he had the
        audacity to question my decision" [syn: {audaciousness}]