Source : Webster's Revised Unabridged Dictionary (1913)

Areopagus \Ar`e*op"a*gus\, n. [L., fr. Gr. ?, and ? ?, hill of
   Ares (Mars' Hill).]
   The highest judicial court at Athens. Its sessions were held
   on Mars' Hill. Hence, any high court or tribunal

Source : WordNet®

Areopagus
     n 1: a hill to the west of the Athenian acropolis where met the
          highest governmental council of ancient Athens and later
          a judicial court
     2: the highest governmental assembly in ancient Athens (later a
        judicial court)