version vs retroversion

version and retroversion both are nouns.

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

As nouns, retroversion is a hyponym of version; that is, retroversion is a word with a more specific, narrower meaning than version:

version: a written communication in a second language having the same meaning as the written communication in a first language
retroversion: translation back into the original language

Other hyponyms of version include mistranslation, crib, pony, trot, caption, subtitle, supertitle, surtitle.

version (noun)	retroversion (noun)
manual turning of a fetus in the uterus (usually to aid delivery)	returning to a former state
a mental representation of the meaning or significance of something	translation back into the original language
something a little different from others of the same type	a turning or tilting backward of an organ or body part
a written communication in a second language having the same meaning as the written communication in a first language
an interpretation of a matter from a particular viewpoint
a written work (as a novel) that has been recast in a new form