catchphrase vs catchword

catchphrase

noun
  • A repeated expression, often originating in popular culture. 

  • A signature phrase of a particular person or group. 

catchword

noun
  • 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. 

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

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