sesquicentennial Syllabification: (ses·qui·cen·ten·ni·al)Pronunciation: /ˌseskwisenˈtenēəl/Definition of sesquicentennial adjective of or relating to the one-hundred-and-fiftieth anniversary of a significant event. noun a one-hundred-and-fiftieth anniversary. sesquicentennial in other Oxford dictionaries Definition of sesquicentennial in the British & World English dictionary
