willingly

from WordNet (r) 3.0 (2006)

willingly
    adv 1: in a willing manner; "I willingly accept" [syn:
           {willingly}, {volitionally}] [ant: {unwillingly}]

from The Collaborative International Dictionary of English v.0.48

Willingly \Will"ing*ly\, adv.
   In a willing manner; with free will; without reluctance;
   cheerfully. --Chaucer.
   [1913 Webster]

         The condition of that people is not so much to be
         envied as some would willingly represent it. --Addison.
   [1913 Webster]