regress vs regressive

regress is a noun but regressive is not a noun.

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

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

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

regress (verb)	regressive (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