Definition from Wiktionary, the free dictionary
catchword (plural catchwords)
- 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.
- Among theatrical performers, the last word of the preceding speaker, which reminds one that he is to speak next; cue.