forgetting vs omission

forgetting

noun
  • The mental act by which something is forgotten. 

omission

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

  • 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. 

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

  • The act of omitting. 

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