aisle: the area paralleling the nave on the left and right sides and separated from the nave by rows of columns.

ambulatorium (AM-byoo-leh TOR-ee-uhm): a walkway, usually circular, that circumnavigates the sanctified place or center of the church.

apse: a semicircular recess, usually located at the eastern end of a church.

atrium (AY-tree-um): the church’s forecourt, usually located on the western end and, in most cases, surrounded by a portico. In Roman practice, the name designated an inner courtyard of a house.

basilica (beh-SILL-eh-kuh): this common term for a type of Roman civic building became synonymous for “church” in the Christian era. In church classification, the term denotes a structure containing a long hall, divided into a nave and aisles by rows of columns, and a chancel and apse usually at the eastern end.