open up vs breach

open up is not a noun while breach is a noun.

Word	Noun	Adjective	Verb	Adverb
open up	No	No	Yes	No
breach	Yes	No	Yes	No

As verbs, breach is a hyponym of open up; that is, breach is a word with a more specific, narrower meaning than open up:

Other hyponyms of open up include unbar, break open, click open, reopen, unlock, unbolt, unseal, uncork, jimmy, lever, prise, prize, pry, gap, lance.

open up (noun)	breach (noun)
	a failure to perform some promised act or obligation
	a personal or social separation (as between opposing factions)
	an opening (especially a gap in a dike or fortification)

open up (verb)	breach (verb)
make available	make an opening or gap in
become available	act in disregard of laws, rules, contracts, or promises
talk freely and without inhibition
cause to open or to become open
become open
open up an area or prepare a way
start to operate or function or cause to start operating or functioning