The Collaborative International Dictionary of English v.0.48:

Spiteful \Spite"ful\, a.
   Filled with, or showing, spite; having a desire to vex,
   annoy, or injure; malignant; malicious; as, a spiteful person
   or act. --Shak. -- Spite"ful*ly, adv. Spite"ful*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

spitefully
    adv 1: in a maliciously spiteful manner; "pray for them that
           despitefully use us" [syn: despitefully, spitefully]
    2: with spite; in a spiteful manner; "he answered his accusers
       spitefully"