big mouth vs blatherskite

big mouth

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

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

blatherskite

noun
  • A voluble purveyor of nonsense; a blusterer. 

  • A worthless fellow; a deadbeat. 

  • Nonsense or blather; empty talk. 

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