vicious in WordNet English dictionary

1. (of persons or their actions) able or disposed to inflict pain or suffering
   "a barbarous crime"; "brutal beatings"; "cruel tortures"; "Stalin's roughshod treatment of the kulaks"; "a savage slap"; "vicious kicks"
   barbarous  brutal  cruel  fell  roughshod  savage  vicious 
   
2. bringing or deserving severe rebuke or censure
   "a criminal waste of talent"; "a deplorable act of violence"; "adultery is as reprehensible for a husband as for a wife"
   condemnable  criminal  deplorable  reprehensible  vicious 
   
3. having the nature of vice
   evil  vicious 
   
4. marked by deep ill will; deliberately harmful
   "poisonous hate"; "venomous criticism"; "vicious gossip"
   poisonous  venomous  vicious