Synonyms and related words :
antecedent, anterior, basic, before, chief, elementary, essential, exordial, first, foremost, fundamental, headmost, in preparation for, inaugural, inductive, initiatory, introductory, leading, opening, precedent, preceding, precessional, precursory, prefatory, prelim, preliminary, preludial, prelusive, preparative, prerequisite, prevenient, primary, prior, proemial, propaedeutic, provident, provisional, rudimentary