Source : Webster's Revised Unabridged Dictionary (1913)

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

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

Source : WordNet®

unwillingness
     n : the trait of being unwilling; "his unwillingness to
         cooperate vetoed every proposal I made" [ant: {willingness}]