let-out vs shortcoming

let-out

noun
  • An opportunity to avoid or escape from a difficult or unpleasant situation. 

  • The act or an instance of releasing or letting out something. 

shortcoming

noun
  • A deficiency or falling short; failure to attain a goal or ideal. 

How often have the words let-out and shortcoming occurred in a corpus of books? (source: Google Ngram Viewer )