Prequels, as we know, are stories that take place before the original narrative. There are several synonyms for the word "prequels" which can be used to convey the same idea. They include: backstory, antecedent, prehistory, precursor, beginning, prologue, and earlier installment. Each of these words can be used to describe a story that occurs before the main narrative and provides an in-depth understanding of the characters, setting, and plot. Using these synonyms will not only add color and variety to your writing but also help you create a more engaging and diverse storyline.