briefness vs brief

briefness and brief both are nouns.

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

briefness (noun)	brief (noun)
the attribute of being brief or fleeting	a condensed written summary or abstract
the temporal property of being very short	a document stating the facts and points of law of a client's case

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

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