decrepit vs infirm

decrepit and infirm both are adjectives.

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

As adjectives, decrepit and infirm are synonyms defined as:

Other synonyms of decrepit include debile, feeble, rickety, sapless, weak, weakly.

decrepit (adjective)	infirm (adjective)
lacking bodily or muscular strength or vitality	lacking bodily or muscular strength or vitality
worn and broken down by hard use	lacking firmness of will or character or purpose