Source : Webster's Revised Unabridged Dictionary (1913)

Willingly \Will"ing*ly\, adv.
   In a willing manner; with free will; without reluctance;
   cheerfully. --Chaucer.

         The condition of that people is not so much to be
         envied as some would willingly represent it. --Addison.

Source : WordNet®

willingly
     adv : in a willing manner; "I willingly accept" [syn: {volitionally}]
           [ant: {unwillingly}]