retrogression vs reversion

retrogression and reversion both are nouns.

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

As nouns, retrogression and reversion are synonyms defined as:

Other synonyms of retrogression include regress, regression, retroversion.

retrogression (noun)	reversion (noun)
returning to a former state	a failure to maintain a higher state
passing from a more complex to a simpler biological form	turning in the opposite direction
	returning to a former state
	(genetics) a return to a normal phenotype (usually resulting from a second mutation)
	a reappearance of an earlier characteristic
	(law) an interest in an estate that reverts to the grantor (or his heirs) at the end of some period (e.g., the death of the grantee)