big mouth vs over-talkativeness

big mouth

noun
  • A person who talks too much, especially by making exaggerated claims or by inappropriately revealing information. 

  • The mouth of someone who talks too much, especially by making exaggerated claims or by inappropriately revealing information. 

over-talkativeness

How often have the words big mouth and over-talkativeness occurred in a corpus of books? (source: Google Ngram Viewer )