frown vs mouthing

frown

noun
  • A downturn of the corners of the mouth, typically expressing sadness. 

  • A wrinkling of the forehead with the eyebrows brought together, typically indicating displeasure, severity, or concentration. 

verb
  • To repress or repel by expressing displeasure or disapproval; to rebuke with a look. 

  • To manifest displeasure or disapprobation; to look with disfavour or threateningly. 

  • To communicate by frowning. 

  • To have a frown on one's face. 

mouthing

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

  • Ranting; passionate speech devoid of meaning. 

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