Wiktionary
prolegomenous
a. (context literary English) introductory; functioning as a preface or prolegomenon.
Usage examples of "prolegomenous".
As we are now entering upon a book in which the course of our history will oblige us to relate some matters of a more strange and surprizing kind than any which have hitherto occurred, it may not be amiss, in the prolegomenous or introductory chapter, to say something of that species of writing which is called the marvellous.