unwillingly

from WordNet (r) 3.0 (2006)

unwillingly
    adv 1: in an unwilling manner; "he had sinned against her
           unwillingly" [ant: {volitionally}, {willingly}]

from The Collaborative International Dictionary of English v.0.48

Unwilling \Un*will"ing\, a.
   Not willing; loath; disinclined; reluctant; as, an unwilling
   servant.
   [1913 Webster]

         And drop at last, but in unwilling ears,
         This saving counsel, "Keep your piece nine years."
                                                  --Pope.
   [1913 Webster] -- {Un*will"ing*ly}, adv. --
   {Un*will"ing*ness}, n.
   [1913 Webster]