1 [usually singular]
official instructions that explain what someone's job is, what their duties are etc:
The architect's brief is to design an extension that is modern but blends with the rest of the building.
a short spoken or written statement giving facts about a law case:
The ACLU filed a brief (=gave one to the court) opposing the decision.
3 British English law
a law case that a lawyer will argue in a court
a short report about something
in as few words as possible:
We should, in brief, invest heavily in digital systems.
without any details:
Here again are today's headlines in brief.
men's or women's underwear worn on the lower part of the body