brief vs instruct

brief is a noun but instruct is not a noun.

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

As verbs, instruct is a hypernym of brief; that is, instruct is a word with a broader meaning than brief:

Other hypernyms of brief include apprise, apprize.

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

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

brief (verb)	instruct (verb)
give essential information to someone	impart skills or knowledge to
	give instructions or directions for some task
	make aware of