preparatory (adj.)

• antecedent
• anterior
• basic
• chief
• elementary
• essential
• first
• foremost
• fundamental
• inaugural
• inductive
• initiatory
• introductory
• leading
• opening
• precedent
• preceding
• precursory
• prefatory
• preliminary
• preparative
• prerequisite
• prevenient
• primary
• prior
• propaedeutic
• provident
• provisional
• rudimentary