derelict vs broken-down

derelict is a noun but broken-down is not a noun.

Word	Noun	Adjective	Verb	Adverb
derelict	Yes	Yes	No	No
broken-down	No	Yes	No	No

As adjectives, derelict and broken-down are synonyms defined as:

Other synonyms of derelict include bedraggled, dilapidated, ramshackle, tatterdemalion, tumble-down.

derelict (noun)	broken-down (noun)
a ship abandoned on the high seas
a person without a home, job, or property

derelict (adjective)	broken-down (adjective)
in deplorable condition	in deplorable condition
failing in what duty requires	not in working order
forsaken by owner or inhabitants
worn and broken down by hard use