Source : Webster's Revised Unabridged Dictionary (1913)

Archly \Arch"ly\, adv.
   In an arch manner; with attractive slyness or roguishness;
   slyly; waggishly.

         Archly the maiden smiled.                --Longfellow.

Source : WordNet®

archly
     adv : with playful slyness or roguishness [syn: {in an arch manner}]