prate vs shoot one's mouth off

prate

verb
  • To talk much and to little purpose; to be loquacious; to speak foolishly. 

noun
  • Talk to little purpose; trifling talk; unmeaningful loquacity. 

shoot one's mouth off

verb
  • To make reckless or exaggerated statements. 

How often have the words prate and shoot one's mouth off occurred in a corpus of books? (source: Google Ngram Viewer )