breakup vs breach

breakup and breach both are nouns.

Word	Noun	Adjective	Verb	Adverb
breakup	Yes	No	No	No
breach	Yes	No	Yes	No

As nouns, breach is a hyponym of breakup; that is, breach is a word with a more specific, narrower meaning than breakup:

Other hyponyms of breakup include break, falling out, rift, rupture, severance, break.

breakup (noun)	breach (noun)
the termination or disintegration of a relationship (between persons or nations)	a failure to perform some promised act or obligation
coming apart	a personal or social separation (as between opposing factions)
	an opening (especially a gap in a dike or fortification)

breakup (verb)	breach (verb)
	make an opening or gap in
	act in disregard of laws, rules, contracts, or promises