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):

spiteful
    adj 1: showing malicious ill will and a desire to hurt;
           motivated by spite; "a despiteful fiend"; "a truly
           spiteful child"; "a vindictive man will look for
           occasions for resentment" [syn: despiteful, spiteful,
           vindictive]

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "spiteful":
   acrid, acrimonious, antagonistic, antipathetic, bearish,
   belligerent, bitchy, bitter, cankered, cantankerous, cattish,
   catty, caustic, churlish, clashing, colliding, conflicting,
   crabbed, cranky, cross, cross-grained, crusty, cussed, despiteful,
   disagreeable, evil, excitable, feisty, fractious, full of hate,
   hateful, hostile, huffish, huffy, invidious, irascible, irritable,
   malevolent, malicious, malign, malignant, mean, ornery, perverse,
   punitive, quarrelsome, rancorous, repugnant, retaliative,
   retaliatory, retributive, retributory, revengeful, set against,
   snappish, sore, spleeny, splenetic, testy, ugly, unforgiving,
   unfriendly, vengeful, venomous, vicious, vindictive, virulent,
   vitriolic, waspish, wicked