Basilica

1. The early Greek name for a royal palace; a large oblong building with double columns and a semicircular apse at one end, frequently used by Christian emperors of Rome for religious purposes.

2. Originally a Roman, large roofed hall erected for transacting business and disposing of legal matters.; later the term came to describe an aisled building with a clerestory. Medieval cathedral plans were a development of the basilica plan type.