no-brainer

Brain drain

- the loss of talented and educated people from one place or country to another place or country where conditions are better

There is a brain drain from many poor countries to wealthy countries where conditions are better.

Brain (someone)

- to strike a person on the head

The spectator was brained in the middle of the match with a tennis ball.

Brain teaser

- a problem for which it is hard to find the answer

My father likes to look in the newspaper for interesting brain teasers.

Brains behind (something)

- the person or people who are responsible for inventing or developing or organizing something

The president of our company is the brains behind the plans to develop the new product.

Brainchild

- an idea that one has thought of without any help from others

The idea for building the new swimming pool was the brainchild of our boss.

Brainless

- stupid

The woman is brainless and has no idea what she is doing.

Brainstorm (something)

- to try to develop an idea

The club members gathered to try and brainstorm some ideas for a spring festival.

Brainwash (someone)

- to make someone believe something that is not true by repeating it again and again

The citizens were brainwashed into thinking exactly what their leader wanted them to think.

exercise one's brain

- to exercise one's intelligence, to use one's brain

I always do puzzles in order to exercise my brain.

Gray matter

- brains, intelligence

The young man seems to be lacking in gray matter.

Have a brainstorm

- to suddenly have a very good idea

I had a brainstorm last night and I now have some good ideas for next year's party.

Have a brainwave

- to have a sudden clever idea

Last night, I had a brainwave and had some good ideas about what to do at my job.

Have a stroke

- to suddenly become (partially or totally) paralyzed because of an interruption in the blood supply to the brain

The driver had a stroke just before the accident on the highway.

Have (something) on the brain

- to be obsessed with something, to never stop thinking or talking about something

The boy has cars on the brain and he does not think of anything else.

no-brainer

- something that is easy to do or understand and does not need much intelligence

It is a no-brainer that if you do not study then your marks will not be good.

pick the brains of (someone) or pick (someone's) brains

- to talk to someone in order to get some information about something

We picked the brains of the official who was talking about the pollution problem.

rack one`s brain

- to try hard to think of something or remember something

I racked my brain to try and decide what to do about the computer problem.