The word brain is almost always a noun. It is seldom used as a verb.
1) an organ of soft nervous tissue contained in the skull of vertebrates, functioning as the coordinating center of sensation and intellectual and nervous activity: [as modifier] : a brain tumor.
- (brains) the substance of an animal’s brain used as food.
2) intellectual capacity: I didn’t have enough brains for the sciences
- (the brains) informal a clever person who supplies the ideas and plans for a group of people: Tom was the brains of the outfit.
- a person’s mind: a tiny alarm bell began to ring in her brain.
- an exceptionally intelligent person: he was known more as a snappy dresser than a brain.
Fun things to do
Exercise your brain. Play the matching game. There are many ways we use the word brain in the English language. Here are a few:
1) brain fart _____ a) medical practitioner operating on the brain
2) brain-power _____ b) a problem or puzzle
3) brain-dead _____ c) a lot of highly trained people leaving a country or company
4) brain surgeon _____ d) temporary inability to think or remember something
5) brain freeze _____ e) extremely stupid (informal and unkind)
6) brain-teaser _____ f) mental ability or intelligence
7) brain drain _____ g) head pain caused by consuming something very cold
(from the New Oxford American Dictionary online)