preface

Concise Oxford English Dictionary © 2008 Oxford University Press:
preface /ˈprɛfəs/

▶noun

• 1 an introduction to a book, typically stating its subject, scope, or aims.

• 2 Christian Church the introduction to the central part of the Eucharist.

▶verb

• 1 provide with a preface.

• 2 (preface something with/by) introduce or begin a speech or event with or by doing something.

– derivatives
prefatory /ˈprɛfət(ə)ri/ adjective.

– origin ME: via OFr. from med. L. praefatia, alt. of L. praefatio(n-) ‘words spoken beforehand’, from praefari (v.), from prae ‘before’ + fari ‘speak’.