Source : Webster's Revised Unabridged Dictionary (1913)

Impudently \Im"pu*dent*ly\, adv.
   In an impudent manner; with unbecoming assurance;
   shamelessly.

         At once assail With open mouths, and impudently rail.
                                                  --Sandys.

Source : WordNet®

impudently
     adv : in an impudent or impertinent manner; "a lean, swarthy
           fellow was peering through the window, grinning
           impudently" [syn: {impertinently}, {saucily}, {pertly},
            {freshly}]