Voluble is a word ultimately derived from the Latin verb volvere, meaning "to roll," that describes an individual who speaks easily and often—someone whose words smoothly roll off their tongue, so to speak.

What does it mean if someone is believable?

: capable of being believed especially as within the range of known possibility or probability. Other Words from believable Synonyms & Antonyms Example Sentences Learn More About believable.

Is voluble positive or negative?

Both talkative and voluble can carry the negative connotation of someone who likes to talk too much, while a brilliant conversationalist suggests to me someone who would be popular on TV chat shows.