Prefatory (adjective)

1. Serving as an introduction or preface.
2. Serving as a preliminary statement or remark.

Origin:

Late latin praefatorius, from latin praefari, to say beforehand, from prae- + fari to speak.

Examples:

1. The prefatory remarks in the book provide context for the author's work.
2. The prefatory words of the play introduced the setting and characters.
3. The prefatory notes offered some background on the manuscript.
4. In the prefatory chapter, the author explains the purpose of the book.
5. The prefatory remarks set the stage for the speech to come.