basilica
a civic building for legal and other civic proceedings; rectangular in plan with the entrance on the long side
nave
a central area of an ancient Roman basilica/church, demarcated from aisles by piers or columns
apse
a recess, usually semicircular, in the wall of a Roman basilica or at the east end of a church
clerestory
a fenestrated part of a building that rises above the roofs of the other parts
narthex
a porch or vestibule of a church
transept
the part of church with an axis that crosses the nave at a right angle
piers
verticle, freestanding masonry support
buttress
exterior masonry structure that opposes lateral thrush of arch or vault
rotunda
circular area under a dome
baldicchino
canopy on columns, frequently built over an altar
cruciform
cross shaped
nimbus
halo of aureole appearing around the head of a holy figure ot signify divinity
codex and vellum
separate panels of vellum (parchment) bound together at one side
diptych
two-paneled painting or altar-piece