Roget's Thesaurus of English Words and Phrases by Peter Mark Roget

forerunner, vancourier†, avant-coureur [Fr.], pioneer, prodrome†, prodromos†, prodromus†, outrider; leader, bellwether; herald, harbinger; foreboding; dawn; avant-courier, avant-garde, bellmare†, forelooper†, foreloper†, stalking-horse, voorlooper [Afrik.], voortrekker [Afrik.]. prelude, preamble, preface, prologue, foreword, avant-propos [Fr.], protasis†, proemium†, prolusion†, proem, prolepsis [Gramm.], prolegomena, prefix, introduction; heading, frontispiece, groundwork; preparation &c 673; overture, exordium [Lat.], symphony; premises. prefigurement &c 511; omen &c 512. Adj. precursory; prelusive, prelusory, preludious†; proemial†, introductory, prefatory, prodromous†, inaugural, preliminary; precedent &c (prior) 116. Phr. a precedent embalms a principle [Disraeli].