decrepit vs derelict

decrepit is not a noun while derelict is a noun.

Word	Noun	Adjective	Verb	Adverb
decrepit	No	Yes	No	No
derelict	Yes	Yes	No	No

As adjectives, decrepit and derelict are synonyms defined as:

Other synonyms of decrepit include creaky, flea-bitten, run-down, woebegone.

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

decrepit (adjective)	derelict (adjective)
lacking bodily or muscular strength or vitality	in deplorable condition
worn and broken down by hard use	failing in what duty requires
	forsaken by owner or inhabitants
	worn and broken down by hard use