| Term | Definition |
| apse | semicircular recess at one end of a Christian church |
| catacomb | underground corridors used for burial |
| codex | pages of vellum or parchment bound together; predecessor of modern book |
| confraternity | an association of Christian families pooling funds to purchase burial sites |
| gallery | passageway three to four feet wide dug below the surface of a catacomb |
| cathedra | Latin for bishop's chair |
| narthex | porch or vestibule of a church |
| orans or orant | praying figure with raised hands |
| cubicula | small rooms serving as mortuary chapels in the catacombs |
| transept | portion of a cruciform church with an axis that crosses the main axis at right angles |
| vellum | skin of unborn calf used for writing material |
| diptych | two hinged, carved panels |
| Ravenna | last capital of the Western Roman Empire |
| Honorius | moved capital of Western Empire from Milan to Ravenna |
| loculi | catacomb niches to receive the dead |
| Galla Placidia | sister of Honorius |
| Junius Bassus | prefect of Rome |
| Dura-Europos | distant outpost of the Roman Empire located on the Euphrates |
| folios | seperate leaves enclosed within a cover and bound together at one side of the codex |
| ambulatory | passage around the apse of a church |