regressive vs regress

regressive is not a noun while regress is a noun.

Word	Noun	Adjective	Verb	Adverb
regressive	No	Yes	No	No
regress	Yes	No	Yes	No

regressive (noun)	regress (noun)
	returning to a former state
	the reasoning involved when you assume the conclusion is true and reason backward to the evidence

regressive (adjective)	regress (adjective)
opposing progress; returning to a former less advanced state
(of taxes) adjusted so that the rate decreases as the amount of income increases

regressive (verb)	regress (verb)
	go back to bad behavior
	get worse or fall back to a previous condition
	go back to a previous state
	go back to a statistical means