A basilica is a type of large, public building that was originally used as a court of law in ancient Rome. The term basilica part refers to the three main parts of a basilica: the NAVE (4 letters), AISLE (5 letters), and APSE (4 letters). The NAVE is the central area of the basilica, where the congregation gathers for worship. The AISLE is the long, narrow passageway that runs along the sides of the NAVE. The APSE is the semicircular or polygonal end of the basilica, which often contains the altar.