Source : Webster's Revised Unabridged Dictionary (1913)

Vengeful \Venge"ful\, a.
   Vindictive; retributive; revengeful. ``Vengeful ire.''
   --Milton. -- {Venge"ful*ly}, adv.

Source : WordNet®

vengeful
     adj : disposed to seek revenge or intended for revenge; "more
           vindictive than jealous love"- Shakespeare;
           "punishments...essentially vindictive in their nature"-
           M.R.Cohen [syn: {revengeful}, {vindictive}]