catchword

noun4

1. •
   A word or expression repeated until it becomes representative of a particular group or time; a slogan or buzzword.

   • One could give a long list of such intellectual fashions and catchwords which in the course of two or three generations have in turn dominated the thinking of the intellectual. — 1949
2. •
   A word printed (often in large or bold type) at the head of a page or other section of text, serving to draw a reader's attention or summarise contents, especially in a reference work; a heading.
3. •
   The last word of a speech, serving as a cue for the next speaker.
4. •
   (historical) A word at the end of a book page that repeats the first word from the following page. (Such words served as aids to the bookbinder (to check rapidly for correct placement of leaves) and were also viewed by some readers as aids to smooth reading.)

   • While he prayed he knelt on his red handkerchief and read above his breath from a thumb blackened prayerbook wherein catchwords were printed at the foot of every page. — 1916