prologue

Etymology

From Middle English prologue, prologe, from Old French prologue, from Latin prologus, from Ancient Greek πρόλογος (prólogos).

noun

1. A speech or section used as an introduction, especially to a play or novel.
   “H'm !” he said, “so, so—it is a tragedy in a prologue and three acts. I am going down this afternoon to see the curtain fall for the third time on what … will prove a good burlesque ; but it all began dramatically enough. It was last Saturday […] that two boys, playing in the little spinney just outside Wembley Park Station, came across three large parcels done up in American cloth. […]” 1905, Baroness Emmuska Orczy, chapter 2, in The Lisson Grove Mystery
2. One who delivers a prologue.
3. (computing) A component of a computer program that prepares the computer to execute a routine.
4. (cycling) An individual time trial before a stage race, used to determine which rider wears the leader's jersey on the first stage.

verb

1. To introduce with a formal preface, or prologue.