Real Dictionary

brief
If you are brief, you say what you want to say in as few words as possible.
adjective: A brief speech or piece of writing does not contain too many words or details.
adjective: Something that is brief lasts for only a short time.

brief in American English
a summary or abstract
of short duration or extent
to make a summary of
adjective: lasting or taking a short time; of short duration
noun: a short and concise statement or written item

brief in British English
adjective: short in duration
noun: a condensed or short statement or written synopsis; abstract