Vocabulary through pictures: brain

brain

1

organ

 [countable] the organ inside your head that controls how you think, feel, and move:

Messages from the brain are carried by the central nervous system.

the chemistry of the brain

the human brain

the right/left hemisphere of the brain (=the right or left side of the brain)

Emotional responses are a function of the right hemisphere of the brain.

She died of a brain tumour.

brain tissue/cell

2

intelligence

 [countable usually plural, uncountable] the ability to think clearly and learn quickly:

If you had any brains, you'd know what I meant.

The job requires brains.

Something's addled your brains (=made you confused).

Come on, use your brain, John.

3

person

 [countable usually plural] informal someone who is intelligent, with good ideas and useful skills:

Some of our best brains are leaving the country to work in the US.

➔ brain drain

4

food

 [uncountable] also brains [plural] the brain of an animal, used as food

5

 have something on the brain

informal to be always thinking about something:

I've got that song on the brain today.

6

 be the brains behind/of something

to be the person who thought of and developed a particular plan, system, or organization, especially a successful one:

Danny's definitely the brains of the project.

7

 brain dead

a) in a state where your brain has stopped working properly even though your heart may still be beating

b) informal in a state in which you seem stupid or uninteresting, especially because you live a boring life or are very tired

8

 brain box

British English informal a very intelligent person

➔ bird-brain, hare-brained

 ; ➔ beat your brains out

 at beat1(22)

 ; ➔ pick somebody's brains

 at pick1 (7)

 ; ➔ rack your brain(s)

 at rack2 (2)

Definition from the Longman Dictionary of Contemporary English
Advanced Learner's Dictionary.