Con ‧ gre ‧ ga ‧ tion ‧ al ‧ is ‧ m /ˌkɒŋɡrəˈɡeɪʃ ə nəlɪz ə m, ˌkɒŋɡrɪˈɡeɪʃ ə nəlɪz ə m $ ˌkɑːŋ-/ BrE AmE noun [uncountable]
a type of Christianity in which each congregation is responsible for making its own decisions
—Congregational adjective
—Congregationalist noun [countable]