breach of duty vs breach

breach of duty and breach both are nouns.

Word	Noun	Adjective	Verb	Adverb
breach of duty	Yes	No	No	No
breach	Yes	No	Yes	No

As nouns, breach is a hypernym of breach of duty; that is, breach is a word with a broader meaning than breach of duty:

breach of duty (noun)	breach (noun)
a breach of due care	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)

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