The Collaborative International Dictionary of English v.0.48:

Preface \Pref"ace\ (?; 48), n. [F. pr['e]face; cf. Sp. prefacio,
   prefacion, It. prefazio, prefazione; all fr. L. praefatio,
   fr. praefari to speak or say beforehand; prae before + fari,
   fatus, to speak. See Fate.]
   1. Something spoken as introductory to a discourse, or
      written as introductory to a book or essay; a proem; an
      introduction, or series of preliminary remarks.
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            This superficial tale
            Is but a preface of her worthy praise. --Shak.
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            Heaven's high behest no preface needs. --Milton.
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   2. (R. C. Ch.) The prelude or introduction to the canon of
      the Mass. --Addis & Arnold.
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   Proper preface (Ch. of Eng. & Prot. Epis. Ch.), a portion
      of the communion service, preceding the prayer of
      consecration, appointed for certain seasons.
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   Syn: Introduction; preliminary; preamble; proem; prelude;
        prologue.
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The Collaborative International Dictionary of English v.0.48:

Preface \Pref"ace\, v. t. [imp. & p. p. Prefaced; p. pr. & vb.
   n. Prefacing.]
   To introduce by a preface; to give a preface to; as, to
   preface a book discourse.
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The Collaborative International Dictionary of English v.0.48:

Preface \Pref"ace\, v. i.
   To make a preface. --Jer. Taylor.
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WordNet (r) 3.0 (2006):

preface
    n 1: a short introductory essay preceding the text of a book
         [syn: foreword, preface, prolusion]
    v 1: furnish with a preface or introduction; "She always
         precedes her lectures with a joke"; "He prefaced his
         lecture with a critical remark about the institution" [syn:
         precede, preface, premise, introduce]