brain ( brains plural )
1 n-count Your brain is the organ inside your head that controls your body's activities and enables you to think and to feel things such as heat and pain.
Her father died of a brain tumour.
2 n-count Your brain is your mind and the way that you think.
usu poss N
Once you stop using your brain you soon go stale..., Stretch your brain with this puzzle.
3 n-count If someone has brains or a good brain, they have the ability to learn and understand things quickly, to solve problems, and to make good decisions.
I had a good brain and the teachers liked me.
4 n-count If someone is thebrains behind an idea or an organization, he or she had that idea or makes the important decisions about how that organization is managed.
INFORMAL usu pl, the N behind/of n
Mr White was the brains behind the scheme..., Some investigators regarded her as the brains of the gang.
5 If you pick someone's brains, you ask them to help you with a problem because they know more about the subject than you.
pick someone's brains phrase V inflects
Why should a successful company allow another firm to pick its brains?
to rack your brains →
If someone suffers brain damage, their brain is damaged by an illness or injury so that they cannot function normally. n-uncount
He suffered severe brain damage after a motorbike accident.
Someone who is brain-damaged has suffered brain damage. adj
The accident left the boy severely brain-damaged and almost totally reliant on others.
brain-dead , brain dead, braindead
1 adj If someone is declared brain-dead, they have suffered brain death.
2 adj If you say that someone is brain-dead, you are saying in a cruel way that you think they are very stupid., (disapproval)
Brain death occurs when someone's brain stops functioning, even though their heart may be kept beating using a machine. n-uncount
When people talk about a brain drain, they are referring to the movement of a large number of scientists or academics away from their own country to other countries where the conditions and salaries are better. n-sing
brain teaser ( brain teasers plural ) , brain-teaser A brain teaser is a question, problem, or puzzle that is difficult to answer or solve, but is not serious or important. n-count