retrogression vs retroversion

retrogression and retroversion both are nouns.

Word	Noun	Adjective	Verb	Adverb
retrogression	Yes	No	No	No
retroversion	Yes	No	No	No

As nouns, retrogression and retroversion are synonyms defined as:

Other synonyms of retrogression include regress, regression, reversion.

retrogression (noun)	retroversion (noun)
returning to a former state	returning to a former state
passing from a more complex to a simpler biological form	translation back into the original language
	a turning or tilting backward of an organ or body part