Dionysius of Halicarnassus Syllabification: (Di·o·ny·si·us of Hal·i·car·nas·sus)Pronunciation: /ˌhalikärˈnasəs/Definition of Dionysius of Halicarnassus (1st century bc), Greek historian, literary critic, and rhetorician. He lived in Rome from 30 bc and is best known for his detailed history of the city, written in Greek. Dionysius of Halicarnassus in other Oxford dictionaries Definition of Dionysius of Halicarnassus in the British & World English dictionary