adulterine unlicensed castle
apse circular or polygonal end of a tower or chapel
arcading rows of arches supported on columns
arrow-loop or slit long, narrow (usually vertical) opening in wall or battlements. Round or triangular ends were for cross-bows, as were horizontal cross-slits which gave greater range
ashlar blocks of smooth, squared stone of any kind
bailey or ward courtyard within the castle walls
barbican outward defensive continuation of a gateway or entrance
barmkin, bawn yard surrounded by outer defensive walling
barrel vault semicircular roof (stone or timber)
bartizan small turret projecting from the corner or flank of a tower or wall, usually at the top
bastion tower or turret projecting from a wall or at the junction of two walls
battlements or crenellation the parapet of a tower or wall with indentations or openings (embrasures or crenelles) alternating with solid projections (merlons)
belfry tall moveable tower on wheels used in sieges
buttress projecting pillar added to strengthen a wall
corbel stone bracket projecting from a wall or corner
cross-wall internal dividing wall in a great tower
curtain general word for walling enclosing a courtyard. Sited between towers, or tower and gatehouse, and appearing to hang between them
donjon alternative name for a great tower
drawbridge wooden bridge (which could be raised and lowered) across a ditch or moat
dressing carved or smooth stonework around openings and along edges
forebuilding structure on the outside wall of a great tower protecting the entrance and all or part of the approaching stairs. Some forebuildings contained chambers and chapels over the stairs
gallery long narrow passage or room
garderobe latrine
gatehouse room over the castle entrance
great tower or keep the main tower of a castle
gun loop or gun port opening in a wall for a gun
hoarding defensive covered wooden gallery placed above a tower or curtain. Floor was slatted to allow defenders to drop missiles or liquids on to besiegers
jamb straight side of a doorway, archway or window
light windowpane or window division
lintel horizontal beam of wood or stone positioned across the top of an opening
machiolation projecting part of a stone or brick parapet with holes in the floor, as in hoarding
mangonel stone-throwing machine
meurtrière or murder hole opening in the roof or a gateway or part of gatehouse over an entrance. Popularly believed to be used in the same way as hoardings, but might have enabled defenders to channel water to wooden areas set on fire by attackers
motte a mound on which a castle was built (man-made or natural)
oriel window projecting curved or polygonal window
oubliette dungeon or pit reached by trap-door used for holding prisoners (in Scotland a pit prison)
palisade a defensive fence
pele tower small tower house
pilaster buttress buttress with a projection, positioned in corner or mid-wall
pipe rolls accounts prepared annually by sheriffs for the king
plantation castle castles built in Ireland on land given to those who would support the Crown
portcullis wood and iron grille-pattern gate, raised and lowered in grooves at an entrance
postern small gateway, usually at the side or rear of a castle
quatrefoil four-lobed, six-foil six-lobed; trefoil three-lobed
quoin dressed corner stone at an angle of a building
relieving arch arch built in a wall to relieve the thrust on another opening
revet face with a layer of stone for more strength. Some earth mottes were revetted with stone
rib vaulting arched roof with ribs of raised moulding at the groins (junction of two curved surfaces)
rubble uncut or only roughly shaped stone, for walling
scarp inner wall or slope of a ditch or moat (counterscarp: outer wall or slope)
slight to damage or destroy a castle to render it unfit for use
solar lord’s parlour or private quarters
stepped recessed in a series of ledges
stronghouse a mansion capable of being defended
turret small tower
wall-walk path along the top of a wall protected by a parapet
wing wall wall descending the slope of a motte
yett iron gates protecting an entrance