a start, beginning.

a subject to be discussed.

a putting forth a subject for disucssing; a proposing.

an introductory statement to a book by its author, explaining in brief the purpose and scope, and also expressing acknowledgment of assistance from others, etc.; preface.

(drama.) an introduction to a play, esp., introductory lines spoken by a member of the cast before a dramatic performance; a prologue; a prelude.