incapacitate vs invalid

incapacitate is not a noun while invalid is a noun.

Word	Noun	Adjective	Verb	Adverb
incapacitate	No	No	Yes	No
invalid	Yes	Yes	Yes	No

As verbs, incapacitate and invalid are synonyms defined as:

Other synonyms of incapacitate include disable, handicap.

incapacitate (noun)	invalid (noun)
	someone who is incapacitated by a chronic illness or injury

incapacitate (adjective)	invalid (adjective)
	having no cogency or legal force
	no longer valid

incapacitate (verb)	invalid (verb)
injure permanently	injure permanently
make unable to perform a certain action	force to retire, remove from active duty, as of firemen