blabbermouth vs conversationist

blabbermouth

noun
  • A person who talks excessively. 

  • A gossip. 

  • A kind of foam-dispensing nozzle used in firefighting at airports. 

conversationist

noun
  • Someone skilled in the art of conversation. 

How often have the words blabbermouth and conversationist occurred in a corpus of books? (source: Google Ngram Viewer )