brain in WordNet English dictionary

1. that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
   brain  encephalon 
   
2. mental ability
   "he's got plenty of brains but no common sense"
   brain  brainpower  learning ability  mental capacity  mentality  wit 
   
3. that which is responsible for one's thoughts and feelings; the seat of the faculty of reason
   "his mind wandered"; "I couldn't get his words out of my head"
   mind  head  brain  psyche  nous 
   
4. the brain of certain animals used as meat
   brain 
   
5. someone who has exceptional intellectual ability and originality
   "Mozart was a child genius"; "he's smart but he's no Einstein"
   genius  mastermind  brain  brainiac  Einstein 
   

1. hit on the head
   brain 
   
2. kill by smashing someone's skull
   brain