pro·logue / ˈprōˌlôg; -ˌläg/ • n. a separate introductory section of a literary or musical work: this idea is outlined in the prologue. ∎  an event or action that leads to another event or situation: civil unrest in a few isolated villages became the prologue to widespread rebellion. ∎  (in professional cycling) a short preliminary time trial held before a race to establish a leader. ∎  the actor who delivers the prologue in a play.

prologue preface to a discourse or drama XIII; speaker of this XVI. — (O)F. — L. prologus — Gr. prólogos, f. PRO-2 + lógos speech.