1) Christian term 
In Christianity, a church service is a formalized period of communal worship, often but not exclusively occurring on Sunday, or Saturday in the case of those churches practicing seventh-day Sabbatarianism. The church service is the gathering together of Christians to be taught the `Word of God` (the Christian Bible) and encouraged in their faith.....
[n] - a service conducted in a church
church noun a service conducted in a house of worship; `don`t be late for church`