legal brief vs brief

legal brief and brief both are nouns.

Word	Noun	Adjective	Verb	Adverb
legal brief	Yes	No	No	No
brief	Yes	Yes	Yes	No

As nouns, legal brief and brief are synonyms defined as:

legal brief and brief: a document stating the facts and points of law of a client's case

legal brief (noun)	brief (noun)
a document stating the facts and points of law of a client's case	a condensed written summary or abstract
	a document stating the facts and points of law of a client's case

legal brief (adjective)	brief (adjective)
	concise and succinct
	(of clothing) very short
	of short duration or distance

legal brief (verb)	brief (verb)
	give essential information to someone