retrogress vs regress

retrogress is not a noun while regress is a noun.

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

As verbs, retrogress and regress are synonyms defined as:

Other synonyms of retrogress include fall back, lapse, recidivate, relapse.

As verbs, regress is a hypernym of retrogress; that is, regress is a word with a broader meaning than retrogress:

Other hypernyms of retrogress include retrovert, return, revert, turn back.

As verbs, retrogress and regress are synonyms defined as:

Other synonyms of retrogress include retrograde.

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

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