decrepit vs run-down

decrepit and run-down both are adjectives.

Word	Noun	Adjective	Verb	Adverb
decrepit	No	Yes	No	No
run-down	No	Yes	No	No

As adjectives, decrepit and run-down are synonyms defined as:

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

decrepit (adjective)	run-down (adjective)
lacking bodily or muscular strength or vitality	having the spring unwound
worn and broken down by hard use	worn and broken down by hard use