vers libre vs free verse

vers libre and free verse both are nouns.

Word	Noun	Adjective	Verb	Adverb
vers libre	Yes	No	No	No
free verse	Yes	No	No	No

As nouns, vers libre and free verse are synonyms defined as:

vers libre and free verse: unrhymed verse without a consistent metrical pattern

vers libre (noun)	free verse (noun)
unrhymed verse without a consistent metrical pattern	unrhymed verse without a consistent metrical pattern