superchurch

noun

su·​per·​church ˈsü-pər-ˌchərch 

plural superchurches

: a church with an extremely large membership

By coincidence, another superchurch is calling at the moment: First Baptist of Dallas, the 28,000-member flagship of Southern Baptist Fundamentalism.

—Richard N. Ostling et al.

Word History

First Known Use

1920, in the meaning defined above