precedent

(noun) an example that is used to justify similar occurrences at a later time. Synonyms: case in point.

(noun) (civil law) a law established by following earlier judicial decisions. Synonyms: case law, common law.

(noun) a system of jurisprudence based on judicial precedents rather than statutory laws. Synonyms: common law, case law. Example: "Common law originated in the unwritten laws of england and was later applied in the united states."

(noun) a subject mentioned earlier (preceding in time).

(adj) preceding in time, order, or significance.