Demosthenes Syllabification: (De·mos·the·nes)Pronunciation: /dəˈmäsTHəˌnēz/Definition of Demosthenes (384–322 bc), Athenian orator and statesman. He is known for his political speeches on the need to resist the aggressive tendencies of Philip II of Macedon (the Philippics). Demosthenes in other Oxford dictionaries Definition of Demosthenes in the British & World English dictionary