addition vs omission

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. 

omission

noun
  • Something not done or neglected. 

  • The shortening of a word or phrase, using an apostrophe ( ' ) to replace the missing letters, often used to approximate the sound of speech or a specific dialect. 

  • An instance of those acts, or the thing left out thereby; something deleted or left out. 

  • The act of neglecting to perform an action one has an obligation to do. 

  • The act of omitting. 

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