expression vs mouthing

expression

noun
  • The action of expressing thoughts, ideas, feelings, etc. 

  • A specific blend of whisky. 

  • A colloquialism or idiom. 

  • An arrangement of symbols denoting values, operations performed on them, and grouping symbols. 

  • The process of translating a gene into a protein. 

  • A facial appearance usually associated with an emotion. 

  • (manufacturing) The act of pressing or squeezing out. 

  • A particular way of phrasing an idea. 

  • A piece of code in a high-level language that returns a value. 

  • The tone of voice or sound in music. 

  • emotional involvement or engagement in a text read aloud rendered by the voice of the reciter or the reader 

mouthing

noun
  • Ranting; passionate speech devoid of meaning. 

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

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