addition vs expansion

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. 

expansion

noun
  • An act, process, or instance of expanding. 

  • A new addition. 

  • A product to be used with a previous product. 

  • That which is expanded; expanse; extended surface. 

  • The operation of steam in a cylinder after its communication with the boiler has been cut off, by which it continues to exert pressure upon the moving piston. 

  • The replacement of a short name (e.g., acronym, initialism, alphanumeric symbol, abbreviation) with the longer name that is synonymous with it, as when spelling out acronyms to ensure clarity for a general audience. 

  • The string of text thus substituted. 

  • The fractional change in unit length per unit length per unit temperature change. 

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