Phocis, a province of ancient Greece, W. of Boeotia, and N. of the Gulf of Corinth; was traversed by the mountain range of Parnassus, and contained the oracle of Apollo at Delphi; allied to Athens in the Peloponnesian War, the Phocians were crushed in the "Sacred War" after ten years' fighting by Philip of Macedon, 346 B.C.