Source : Webster's Revised Unabridged Dictionary (1913)

Catchword \Catch"word`\, n.
   1. Among theatrical performers, the last word of the
      preceding speaker, which reminds one that he is to speak
      next; cue.

   2. (Print.) The first word of any page of a book after the
      first, inserted at the right hand bottom corner of the
      preceding page for the assistance of the reader. It is
      seldom used in modern printing.

   3. A word or phrase caught up and repeated for effect; as,
      the catchword of a political party, etc.

Source : WordNet®

catchword
     n : a favorite saying of a sect or political group [syn: {motto},
          {slogan}, {shibboleth}]