prefacing

noun

1. R.C.Ch. the introduction to the Canon of the Mass, ending with the Sanctus
2. an introductory statement to a book, telling its purpose, plan, etc., esp. a brief one written by the book's author
3. something preliminary or introductory; prelude

transitive verb prefaced, prefacing

1. to furnish or introduce with a preface
2. to be or serve as a preface to; begin