Catchword

Part of speech: noun (n.)

1. Among theatrical performers, the last word of the preceding speaker, which reminds one that he is to speak next; cue.

2. 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.