Aristarchus2 Syllabification: (Ar·is·tar·chus)Pronunciation: /ˌarəˈstärkəs/Definition of Aristarchus (circa 217–145 bc), Greek scholar; known as Aristarchus of Samothrace. He is noted for his editions of the writings of Homer and other Greek authors. Aristarchus in other Oxford dictionaries Definition of Aristarchus in the British & World English dictionary