prefatory

• præfatory (obsolete)

From Medieval Latin *praefator +‎ -ory (“agent”), from Medieval Latin prefatia (whence preface), for classical Latin praefatio (“a saying beforehand”) – see preface for details.[1]

Note that this is borrowed from Latin, not derived in English from preface, as in occasional misspelling *prefecatory.

prefatory (comparative more prefatory, superlative most prefatory)

1. Introductory, preliminary, serving as a prelude or preface. [from 1670s]

Rather formal and academic – preliminary is less formal, while introductory is less formal still. A casual alternative is to use some form of start, as in “To start…” or “Let me start by saying…”, as opposed to “By way of prefatory remarks…”.

• foreparty