prologize
/ˈproʊləˌɡaɪz/
verb
- To speak or write a prologue; to introduce something, especially a speech, book, or performance.
- The author chose to prologize her novel with a poem about the sea.
- Before the main debate, the moderator will prologize with a brief overview of the rules.
- In ancient Greek theater, an actor would often prologize to explain the story's background.