Ionia Syllabification: (I·o·nia)Pronunciation: /īˈōnēə/Definition of Ionia in classical times, the central part of the west coast of Asia Minor, which had long been inhabited by Hellenic people (the Ionians) and was again colonized by Greeks from the mainland from about the 8th century bc. Ionia in other Oxford dictionaries Definition of Ionia in the British & World English dictionary