betrayer vs no-show

betrayer

noun
  • Someone who betrays, or reveals confidential information; a squealer or informer. 

no-show

noun
  • A person or group that does not show up. 

  • An absence; failure to show up or to make a scheduled appearance, especially at a hotel or a place of employment. 

verb
  • To fail to show up for something. 

How often have the words betrayer and no-show occurred in a corpus of books? (source: Google Ngram Viewer )