Source : Webster's Revised Unabridged Dictionary (1913)

Disdainful \Dis*dain"ful\, a.
   Full of disdain; expressing disdain; scornful; contemptuous;
   haughty.

         From these Turning disdainful to an equal good.
                                                  --Akenside.
   -- {Dis*dain"ful*ly}, adv. -- {Dis*dain"ful*ness}, n.

Source : WordNet®

disdainfulness
     n : the trait of displaying arrogance by patronizing those
         considered inferior [syn: {condescension}, {superciliousness}]