Prologue

Part of speech: noun (n.)

1. The preface or introduction to a discourse, poem, or performance; as, the prologue of Chaucer's "Canterbury Tales;" esp., a discourse or poem spoken before a dramatic performance

2. One who delivers a prologue. [R.] Shak.

Part of speech: verb (v.)

To introduce with a formal preface, or prologue. [R.] Shak.