What is another word for "groundwork"?

Roget's Thesaurus (1911) lists these synonyms for "groundwork": and, antecedent, article, avant-courier, being, bellwether, blood, bodily, body, corporeal, corporeity, creature, dawn, element, essential, essentially, existence, exordium, flesh, foreboding, forerunner, foreword, frontispiece, harbinger, heading, herald, hypostasis, hypostatic, inaugural, introduction, introductory, item, leader, material, materiality, matter, nature, object, omen, outrider.