catchword vs guideword

catchword

noun
  • A word under the right-hand side of the last line on a book page that repeats the first word on the following page. 

  • A word or expression repeated until it becomes representative of a party, school, business, or point of view. 

  • The last word of a speech, serving as a cue for the next speaker. 

guideword

noun
  • A word that is printed at the top or bottom of the page in a reference work, in order to help readers find a specific entry. 

  • A watchword; a word or phrase that serves as one's guide. 

  • Any of the words in a memo or email that define metadata regarding the message, such as sender, recipient, and subject. 

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