Heilbronn Syllabification: (Heil·bronn)Pronunciation: /ˈhīlˌbrän, -ˌbrôn/Definition of Heilbronn a city in southwestern Germany, on the Neckar River, in Baden-Württemberg; population 121,400 (est. 2006). Heilbronn in other Oxford dictionaries Definition of Heilbronn in the British & World English dictionary