1. Marked by deep ill will; deliberately harmful
   "vicious gossip";
   - poisonous, venomous, viperous, malicious
    
2. (of persons or their actions) able or disposed to inflict pain or suffering
   "vicious kicks";
   - barbarous, brutal, cruel, fell, roughshod, savage
    
3. Having the nature of vice
   "The dog's vicious bark scared the children";
   - evil
    
4. Bringing or deserving severe rebuke or censure
   "a vicious waste of talent";
   - condemnable, criminal, deplorable, reprehensible

See also: beady-eyed, bitchy [informal], cattish [informal], catty [informal], despiteful [archaic], inhumane, leering, malevolent, spiteful, venomed, vindictive, vixenish, wicked, wrong

Encyclopedia: Vicious