catchword

The story

From catch + word.

First known use, by meaning

• from 17th c. 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.)
• from 18th c. A word or expression repeated until it becomes representative of a particular group or time; a slogan or buzzword.
• from 18th c. The last word of a speech, serving as a cue for the next speaker.
• from 19th c. 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.