fallacious vs invalid

fallacious is not a noun while invalid is a noun.

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

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

fallacious (adjective)	invalid (adjective)
involving deception	having no cogency or legal force
based on an incorrect or misleading notion or information	no longer valid
containing or based on a fallacy

fallacious (verb)	invalid (verb)
	injure permanently
	force to retire, remove from active duty, as of firemen