(1) Concise and succinct
"Covered the matter in a brief statement"
(2) (of clothing) very short
"An abbreviated swimsuit"
"A brief bikini"
(3) Of short duration or distance
"A brief stay in the country"
"In a little while"
"It's a little way away"
(4) A condensed written summary or abstract
(5) A document stating the facts and points of law of a client's case
(6) Give essential information to someone
"The reporters were briefed about the President's plan to invade"
- letter (written message)