prologue
n.an introduction at the start of a book, play, or movie. It usually gives you background information or sets the mood for the rest of the story.
n.an introductory section of a literary, dramatic, or musical work. It serves to establish context, provide backstory, or frame the narrative before the main action begins.
“The prologue explains why the two families are fighting.”
“In the play's prologue, a narrator appears on stage to warn the audience about the tragic ending.”
“The author uses a brief prologue to establish the historical setting, ensuring readers understand the political tensions that drive the protagonist's later decisions.”
Often followed by the preposition 'to' when indicating which work it introduces.
From Middle English prologue, prologe, from Old French prologue, from Latin prologus, from Ancient Greek πρόλογος (prólogos). Equivalent to pro- + -logue.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.