Definition of "Brain" :

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

noun: that which is responsible for one's thoughts, feelings, and conscious brain functions; the seat of the faculty of reason

noun: mental ability

"He's got plenty of brains but no common sense."

noun: the brain of certain animals used as meat

noun: someone who has exceptional intellectual ability and originality

verb: kill by smashing someone's skull

verb: hit on the head