Prequel (noun)

A work, especially a book, film, or play, that is set before the main story and provides background information about its characters or events.

Origin:

Late 20th century. from pre- + sequel.

Examples:

1. The movie 'Star Wars: Episode I - The Phantom Menace' is a prequel to the original 'Star Wars' film.
2. The book 'Before Watchmen' is a prequel to the graphic novel 'Watchmen' by Alan Moore.
3. The play 'Romeo and Juliet: The Early Years' is a prequel to Shakespeare's classic tragedy 'Romeo and Juliet'.
4. The novel 'The prequel to 'Pride and Prejudice' is a fascinating look at the characters before they became the beloved figures we know and love.
5. The video game 'BioShock 2' is a prequel to the original 'BioShock' game, exploring the city of Rapture before the events of the first game.