con ‧ gre ‧ ga ‧ tion /ˌkɒŋɡrəˈɡeɪʃ ə n, ˌkɒŋɡrɪˈɡeɪʃ ə n $ ˌkɑːŋ-/ BrE AmE noun [ countable also + plural verb British English ]
1 . a group of people gathered together in a church:
The congregation knelt to pray.
2 . the people who usually go to a particular church:
Several members of the congregation are away.