brain

that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord

mental ability; "he's got plenty of brains but no common sense"

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"

someone who has exceptional intellectual ability and originality; "Mozart was a child genius"; "he's smart but he's no Einstein"

the brain of certain animals used as meat

hit on the head

kill by smashing someone's skull