Congregationalism Syllabification: (Con·gre·ga·tion·al·ism)Pronunciation: /ˌkäNGgrəˈgāSHənlˌizəm/Definition of Congregationalism noun a system of organization among Christian churches whereby individual local churches are largely self-governing. Derivatives Congregationalist noun & adjective Congregationalism in other Oxford dictionaries Definition of Congregationalism in the British & World English dictionary