preface

Etymology

Late 14th century, from Middle English preface, prefas, from Old French preface (from which derives the modern French préface), from Medieval Latin prefātia, for classical Latin praefātiō (“a saying beforehand”), from praefor (“to speak beforehand”), from prae- (“beforehand”) + for (“to speak”).

noun

1. A beginning or introductory portion that comes before the main text of a document or book, typically serving to contextualize or explain the writing of the book and sometimes to acknowledge others' contributions.
   The book included a brief preface explaining the author's motivations for writing.
2. An introduction, or series of preliminary remarks.
3. (Roman Catholicism) A variable prayer forming the prelude or introduction to the Eucharistic Prayer or canon of the Mass, following the Sursum corda dialogue and leading into the Sanctus.
   Meronyms: protocol, embolism, eschatocol
4. A title or epithet.
   […] a black-tie dinner to celebrate on the eve of the ceremony which would remove the preface "Sir" from his name and replace it with the preface "Lord," thought by some to be one of the most potent words in the English language. 2008, W. Bruce Kippen, Lords of the Frontier

verb

1. (transitive) To introduce or make a comment before (the main point).
   Let me preface this by saying that I don't know him that well.
2. (transitive) To give a preface to.
   to preface a book