The word “catchword” is from the world of print.
Two hundred years ago, the last word on a page to be turned began being routinely repeated at the top of the next page to smooth the transition.
Newspapers followed by repeating the last word of an article when it was picked up deeper into the paper.
In the theater, a catchword is the cue for the next actor to start his lines.
A catchphrase is a political or commercial slogan.
The first use of catchwords in a printed book was Tacitus, by John de Spira (1469).
