ˈbrain drain noun
the brain drain a movement of highly skilled or professional people from their own country to a country where they can earn more money

[TahlilGaran] Dictionary of Contemporary English ▲

brain drain
the movement of people with education and skills from their own country to another country where they are paid more for their work.
There is a brain drain of British mathematicians to the United States.

[TahlilGaran] English Idioms Dictionary ▲

brain drain
the loss of talented and educated people from one place/country to other places/countries where conditions are better
There is a brain drain from many poor countries to wealthy countries where conditions are better.

[TahlilGaran] English Idioms Dictionary ▲

brain drain
n., informal
1. The loss of the leading intellectuals and researchers of a country due to excessive emigration to other countries where conditions are better.
Britain suffered a considerable brain drain to the United States after World War II.
2. An activity requiring great mental concentration resulting in fatigue and exhaustion
That math exam I took was a regular brain drain.

[TahlilGaran] English Idioms Dictionary ▲