fluency vs volubility

fluency and volubility both are nouns.

Word	Noun	Adjective	Verb	Adverb
fluency	Yes	No	No	No
volubility	Yes	No	No	No

As nouns, fluency and volubility are synonyms defined as:

fluency and volubility: the quality of being facile in speech and writing

Other synonyms of fluency include articulateness.

fluency (noun)	volubility (noun)
the quality of being facile in speech and writing	the quality of being facile in speech and writing
skillfulness in speaking or writing
powerful and effective language