Congregation (noun)

1. A group of people assembled for religious worship.
2. A community of people sharing a common interest or purpose.

Origin:

Late middle english: from latin congregatio(n-), from congregare 'assemble, gather together'.

Examples:

1. The congregation sang hymns during the service.
2. The congregation at the church was large.
3. The congregation of birdwatchers was gathered at the park.
4. The congregation was pleased with the pastor's sermon.
5. The congregation of alumni met for a reunion.