prequel

/ˈpɹiːkwəl/

IPA: /P R IY1 K W AH0 L/

noun
  1. 1

    In a series of works, an installment that is set chronologically before its predecessor, especially the original narrative or (perhaps improper usage) any narrative work with at least one sequel.

Antonyms

Source: https://en.wiktionary.org/wiki/prequel