| Adulterine: | The term that is used to define a castle built without royal permission when such permission is required. |
| Allure: | A walkway along the top of a wall. |
| Arcade: | An arched covered passageway with columns or piers. |
| Arch: | A typically curved structural member spanning an opening and serves as a wall support above doors and windows. |
| Armoury: | A storehouse for the castle's weapons. |
| Arrow loops: | A vertical narrow slit built into a wall through which arrows are shot. |
Additions will be added to this list over time
