addition vs expression

addition

noun
  • The act of adding anything. 

  • The arithmetic operation of adding. 

  • A dot at the right side of a note as an indication that its sound is to be lengthened one half. 

  • Anything that is added. 

  • A title annexed to a person's name to identify him or her more precisely. 

  • Something added to a coat of arms, as a mark of honour. 

expression

noun
  • A particular way of phrasing an idea. 

  • A specific blend of whisky. 

  • A colloquialism or idiom. 

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

  • 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 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 

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