mouthing vs promulgation

mouthing

noun
  • Ranting; passionate speech devoid of meaning. 

  • The act of forming a shape with the mouth, especially as part of sign language. 

promulgation

noun
  • The act of promulgating or announcing something, especially a proclamation announcing a new law. 

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