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.
the ability to think clearly and learn quickly:
intelligence[countable usually plural, uncountable]
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.
someone who is intelligent, with good ideas and useful skills: ➔ brain drain
person[countable usually plural] informal
Some of our best brains are leaving the country to work in the US.
the brain of an animal, used as food
food[uncountable] also brains [plural]
to be always thinking about something:
I've got that song on the brain today.
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.
in a state where your brain has stopped working properly even though your heart may still be beating
in a state in which you seem stupid or uninteresting, especially because you live a boring life or are very tired
8 British English informal
a very intelligent person