1) A large public building, rectangular in plan, normally featuring a nave flanked by aisles, and an apse. In ancient Roman architecture, basilicas were secular buildings, used as law courts and markets, and for public assemblies. The basilica plan was also was also commonly used for Christian church buildings from the fourth century onwards.
2) For the Catholic church, starting in the 18th century, the term basilica took on a canonical sense, irrespective of the architectural style of the building. Certain churches are granted the status of major or minor basilica, which brings with it privileges and precedence over other churches.