The Collaborative International Dictionary of English v.0.48:

Corypheus \Cor`y*phe"us\ (k?r`?-f?"?s), n.; pl. E. Corypheuses
   (-[e^]z), L. Coryphei (-f?"?). [L. coryphaeus, fr. Gr. ???,
   fr. koryfh` head.] (Gr. Antiq.)
   The conductor, chief, or leader of the dramatic chorus;
   hence, the chief or leader of a party or interest.
   [1913 Webster]

         That noted corypheus [Dr. John Owen] of the Independent
         faction.                                 --South.
   [1913 Webster]