O’er: Over.  Canopy: An ornamental cloth.  Epicurus: Greek Philosopher.  Sardis: Ancient city in Asia.  Philippi: A ruined city in Greece.  Messala: Greek statesman.  Perch’d: Perched.  Presage: To foreshadow future events.  Gorging: Something rises from your throat because of revulsion.  Pompey: Pompeii.