Law . a legal decision or form of proceeding serving as an authoritative rule or pattern in future similar or analogous cases.

any act, decision, or case that serves as a guide or justification for subsequent situations.

preceding; anterior.

noun

antecedent , authority , criterion , exemplar , instance , model , paradigm , example , custom , decision , guideline , preceding , ruling , standard

adjective

antecedent , anterior , earlier , preceding , previous , prior , foregoing , former