open one's mouth vs orate

open one's mouth

verb
  • to speak 

orate

verb
  • To speak formally; to give a speech. 

  • To speak passionately; to preach for or against something. 

adj
  • Competent in oracy; having good speaking skills. 

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