a loss of trained professional personnel to another company, nation, etc., that offers greater opportunity.
Also, brain-drain.
Origin
1960-65
Examples from the web for brain drain
The low pay in professional jobs has led to the brain drain.
Overall, the brain drain actually helps poor countries.
These figures do not necessarily indicate a brain drain.
The region suffers from low standards of living and a serious brain drain, and frustration is widespread.
There is a brain drain the risk takers and educated can't wait to depart.
British Dictionary definitions for brain drain
brain drain
noun
1.
(informal) the emigration of scientists, technologists, academics, etc, for better pay, equipment, or conditions
Slang definitions & phrases for brain drain
brain drain
noun phrase
The loss of useful educated persons, esp professionals, because they can find better conditions elsewhere: Stalled Economy Speeds Puerto Rico's Brain Drain(1960s+ British)
Idioms and Phrases with brain drain
brain drain
The departure of educated or talented persons for better pay or jobs elsewhere, as in The repression of free speech in Germany triggered a brain drain to Britain and America. The term originated about 1960, when many British scientists and intellectuals emigrated to the United States for a better working climate.