Architectural Terminology
A semicircular or polygonal passageway around the apse of a church. Image courtesy of Gretchen Ranger
Apse
A semicircular, polygonal, or rectangular extension at the end of a Roman basilica or a Christian church. Image courtesy of Heather Russell
Anta
In Classical temples, the pilaster like projecting end of a portico wall often framing columns, which are then said to be in antis Image courtesy of Gayle Goudy Kochanski
Arcade
A series of arches supported on piers or columns.  A "blind" arcade is a row of arches applied to the wall as an ornamental feature. Image courtesy of Gayle Goudy Kochanski
Arch
A structural devise, curved in shape, to span an opening by means of wedge-shaped bricks or stones (voussoirs) that support each other by exerting mutual pressure and that are buttressed at the sides. Image courtesy of Gayle Goudy Kochanski
Architrave
A square beam that is the lowest of the three horizontal components of a Classical entablature. Image courtesy of Heather Russell
Archivolt
A molded band carried around an arch. Image courtesy of Gayle Goudy Kochanski
Arcuated
Any form of construction using arches. Image courtesy of Gayle Goudy Kochanski
Ashlar
Building stone that has been squared and finished, and the masonry constructed of such blocks. Courtesy of Heather Russell
Barrel Vault
A half-cylindrical vault, semicircular or pointed in cross section; also called tunnel vault. Image courtesy of Heather Russell
Bay
A vertical compartment of a building in which several such compartments are repeated; each bay mignt be defined by columns, piers, windows, or vaulting units. Michelangelo Museo Capitolino is divided into 7 bays by pilasters. Image courtesy of Phil Gruen
Basilica
In ancient Roman architecture, a large rectangular building used as a tribunal or for other public purposes and generally arranged with nave, aisles, and one or more apses. In Christian architecture, a longitudinal church of related form. Image courtesy of Gayle Goudy Kochanski
Boss
Sculpted ornament of joints, found primarily in vaults. Image courtesy of Gretchen Ranger
Buttress
A projecting mass of masonry serving to provide additional strength for the wall as it resists the lateral thrust exerted by an arch or vault.  Plying Buttress: in a church, a buttress in the form of an arch, or set of arches, that carries the thrust of a nave vault over the side aisle roofs down to a massive external pier. Image courtesy of Gretchen Ranger
Capital
The uppermost part of a column, usually shaped to articulate the joint with the lintel or arch supported; in Classical types, comprising an abacus, echinus, and other carved detail. Image courtesy of Heather Russell
Caryatid
A sculpted female figure used as a support in place of a column or pier. Image courtesy of Heather Russell
Cella
The body and main sanctuary of a Classical temple, as distinct from its portico and other external parts; sometimes used synonymously with naos, the principal room of a temple where the cult statue is housed. Image courtesy of Gayle Goudy Kochanski
Centering
Temporary wooden framework used to hold construction material in place until a vault or arch is self-sustaining. Image courtesy of Gail Gould
Chancel
The eastern portion of a church set apart for the clergy, and often separated from the main body of the church by a screen, rail, or steps.  The term is also used to describe the entire east end of a church beyond the crossing. Image courtesy of Gretchen Ranger
Chevet
A French term used to describe the developed east end of a church, usually a French Gothic cathedral, with its apse, ambulatory, and radiating chapels. Image courtesy of Gretchen Ranger
Choir
The part of a church, generally located toward or in the apse, reserved for clergy and singers.
(This photograph was taken looking down the nave toward the apse.  The choir screen is highlighted, which is just beyond the transept.) Image courtesy of Gretchen Ranger
Clerestory
A part of a building that rises above adjoining roof-tops and is pierced by window openings to admit light to the interior. Image courtesy of Gretchen Ranger
Cloister
An open square court surrounded by a covered ambulatory, often archaded.  It is generally attached to a church or monastery and is distinguished from a secular courtyard by its function as a lace of seclusion and repose. Image courtesy of Gretchen Ranger
Coffering
Recessed panels, square or polygonal, that ornament a vault, ceiling, or the underside (soffit) of an arch. Image courtesy of Gretchen Ranger
Colonnette
A small or greately attenuated, slender column. Image courtesy of Gayle Goudy Kochanski
Colossal/Giant Order
Columns or pilasters that rise through several stories; also called a Giant Order. Image courtesy of Phil Gruen
Column
A vertical, usually cylindrical, support, commonly consisting of a base, shaft, and capital; in Classical archtecture, its parts are governed by proportional rules. Image courtesy of Heather Russell
Composite Order
One of the five Classical orders; favored in late Roman architecture.  On the capital, large conjoined Ionic volutes are combined with the acanthus leaves of the Corinthian order. Image courtesy of Gail Gould
Compound Pier
A pier with columns, shafts, and pilaters attached, sometimes in clusters, to its faces. Image courtesy of Gayle Goudy Kochanski
Corbel
A masonry block projecting from a wall to support a superincumbent element. Image courtesy of Gretchen Ranger
Corbeled Arch
Masonry constructed over a wall opening by a series of courses projecting from each side and stepped progressively further forward until they meet at midpoint; not a true arch.
Corinthian Order
The most richly embellished of the thre orders (Doric, Ionic, and Corinthian) developed by the Greeks, with a tall capital composed of a bell-shaped core (kalathoss) envelped by layers of acanthus leaves terminating in the corner volutes, surmounted by concave-sided abacus. Image courtesy of Gail Gould
Cornice
The uppermost, projecting portion of an entablature; also the crowing horizontal molding of a building or wall. Image courtesy of Heather Russell
Crossing
The area where the nave and transept intersect in a cruciform church, frequently surmounted by a tower or dome.
(This tower is over the crossing). Image courtesy of Gail Gould
Crypt
A vaulted space beneath the pavement of a church, often housing relics or tombs.
Diaphragm Arch
A transverse arch across the nave of a church partitioning the roof into sections. Image courtesy of Gretchen Ranger
Dipteral
Referring to a temple surrounded by a double range of columns. Image courtesy of Gayle Goudy Kochanski
Distyle in Antis
In a Classical temple referring to a portico with two columns between piers (antae) projecting from the cella walls. Image courtesy of Gayle Goudy Kochanski
Dome
A curved vault that is erected on a circular base and that is semicircular, pointed, or bulbous in section.  If raised over a square or polygonal base transitional squinches or pendentives must be inserted at the corners of the base to transform it into a near circle. Image courtesy of Gayle Goudy Kochanski
Doric Order
The column and entablature developed on mainland Greece; the fluted columnar shaft is without a base; its capital is an abacus above a simple cushionlike molding (echinus).  The entablature has a plain architrave, a frieze composd of metopes and triglyphs, and a cornice with projecting blocks (mutules).  In Roman Doric, the colun is slimmer than the Greek prototype, is unfluted, and stands on a low base; the capital is smaller. Image courtesy of Heather Russell
Drum
1. The cylindrical or polygonal wall supporting a dome. Image courtesy of Gayle Goudy Kochanski
2. One of the cylindrical sections comprsing the shaft of a column. Image courtesy of Heather Russell
Dry Masonry
Masonry laid without mortar. Image courtesy of Heather Russell
Echinus
A convex, cushion like molding between the shaft and the abacus in the Doric or Tuscan order; in an Ionic capital, found beneath the volutes, generally in decorated form. Image courtesy of Heather Russel
Engaged Column
A column attached to or appearing to be partly embedded wthin a wall. Images courtesy of Heather Russell (left) and Gayle Goudy Kochanski (right)
Entablature
The upper part of a Classical order comprising architrave, frieze, and cornice. Image courtesy of Heather Russell
Entasis
The slight swelling of the vertical profile of a Classical column as it tapers toward the top to counteract the illusion of concavity that accompanies straight-sided columns. (orange lines exaggerated) Image courtesy of Heather Russell
Exedra
A semicircular recess or niche; a large apse. Image courtesy of Gretchen Ranger
Extrados
The upper surface of an arch or vault. Image courtesy of Gayle Goudy Kochanski
Facade
The principal exterior face of a building, usually the front. Image courtesy of Phil Gruen
Fluting
The shallow concave channels cut vertically into the shaft of a column or pilaster.  In Doric columns, they meet in a sharp edge (arris); in Ionic, Corinthian, and Composite columns, they are separated by a narrow strip.
Image courtesy of Heather Russell
Frieze
A horizontal band, sometimes painted or decorated with sulpture or moldings.  It may run along the upper portion of a wall just beneath a cornice or it may be that part of a classical entablature that lies between the architrave and cornice.  A Doric frieze often has continuous relief sculpture. Image courstesy of Heather Russel
Gable
A triangular element.  It may be the end of a pitched roof framed by the sloping sides.  It also refers to the top of a Gothic panel, or to the triangular area above the portals of a Gothic building. Image courtesy of Gretchen Ranger
Gallery
An upper story projecting from the interior wall of a building, or placed above the aisles of a church.  It may function as a corridor or as an area for assembly or seating. Image courtesy of Gail Gould
Groin Vault
A vault formed when two barrel vaults of identical size intersect at right angles (also called a cross vault). Image courtesy of Gail Gould
Hall Church
A church in which the nave and aisles are the same height, giving the building the appearace of a great hall.
Impost
In a pier, the projecting molding at the springing of an arch.  A rectangular impost block transmits the weight of an arch to a supporting member; it may appear between the capital of a column and the springing of an arch. Image courtesy of Gayle Goudy Kochanski
In Antis
The term used to describe columns placed between the ends of two walls, commonly projecting from the ends of the cella of a small Greek Temple. Image courtesy of Gayle Goudy Kochanski
Intrados
The undersurface (as opposed to extrados) of an arch (or vault); also called a soffit. Image courtesy of Gayle Goudy Kochanski
Intercolumnation
The space between adjacent colunms in a colonnade, frequently determined by some multiple of the diameter of the column itself. Image courtesy of Heather Russell
Ionic Order
One of the five Classical Orders, the Ionic is characterized by a scroll-shaped (voluted) capital element, the presence of dentils in the cornice, and a frieze that mighta contain continuous relief ornament. Image courtesy of Gretchen Ranger
Keystone
The central voussoir at the top of a completed arch. Image courtesy of Gayle Goudy Kochanski
Lancet Window
A tall, slender window with a sharply pointed arch (like a lance), common in early Gothic architecture. Image courtesy of Gretchen Ranger
Lantern
A cylindrical or polygonal structure that crowns a dome, its base usually open to allow light to enter the area below. Image courtesy of Gretchen Ranger
Loggia
An arcade supported by piers or coluns, open on one side at least; either part of a building (as a porch) or a separate structure. Image courtesy of Gayle Goudy Kochanski
Lunette
A semicircular wall area, or opening, above a door or window; when above the portal of a church, often called a tympanum. Image courtesy of Gretchen Ranger
Martyrium
A struction, oftenof central plan, erectred on a site sacred to Christianity, symbolizing an act of martydom or marking the grave of a martyr who died for the faith.
Megaron
The principal hall of an Aegean dwelling, oblong in shape and formed with sloping sides and a flat top, with a passage leading to an underground burial chamber.
Melon Dome/Umbrella Dome
A dome subdivided into individual concave webs; sometimes called an umbrella dome. Image courtesy of Gretchen Ranger
Metope
In the frieze of a Doric order, the rectangular area between tryglyphs; often left plain but sometimes decorated with relief ornament. Image courtesy of Heather Russell
Molding
A sculpted, ornamental band, carved with a distinctive profile or pattern; highly developed in Classical architecture. Image courtesy of Heather Russell
Mullion
A slender upright dividing an opening, usually a window, into two or more sections. Image courtesy of Gayle Goudy Kochanski
Naos
The principal enclosed area of a Greek temple, containing the cult statue of god or goddess. Image courtesy of Gayle Goudy Kochanski
Narthex
A colonnaded porch in front of the facade of a church, in early Chrisian architectue often serving as the fourth side of an atrium; also a transverse vestibule preceding the church nave and aisles. Image courtesy of Gayle Goudy Kochanski
Nave
The central, longitudinal space of a basilican church, separated from the aisles or from side chaples, and extending from the main entrance to the transept or to the apse. Image courtesy of Gretchen Ranger
Niche
A concave recess in a wall, often used to house statuary. Image courtesy of Heather Russell
Oculus
A round window. Image courtesy of Gretchen Ranger
Opisthodomos
The room at the rear of a Greek temple, behind the naos. Image courtesy of Gayle Goudy Kochanski
Order
A system for the forms and relationship of elements in the column and entablature of Classical architecture according to one of five modes:  Doric, Ionic, Corinthian (developed by the Greeks), and Tuscan and Composite (developed by the Romans).
Palladian Motif/Serliana
A triple opening formed by a central semicircular arch springing from the entablature of narrower flanking square-headed bays, used by architect Andrea Palladio.  Also known as a Serliana because it was first illustrated in the architecture treatise of 1537 by Sebastiano Serlio. Image courtesy of Gail Gould
Parapet
A low wall for protection at the edge of a balcony, terrace, roof, bridge, etc. Image courtesy of Gayle Goudy Kochanski
Pedestal
A supporting substructure for a column or statue. Image courtesy of Heather Russell
Pediment
A triangular space formed by the raking cornices (sloping sides) and horizontal cornice of a gabled temple; also used above a door or window.  If the apex or base is split, the pediment is described as broken. Image courtesy of Heather Russell
Pendentive
An inverted, concave, triangular piece of masonry serving as the transition from a square support system to the circular base of a dome. Image courtesy of Gretchen Ranger
Peripteral
Pertaining to a building surrounded by a row of columns on all sides. Image courtesy of Heather Russell
Piano Nobile
The principal reception and living area in an Italian palace, the first floor above the ground. Image courtesy of Gretchen Ranger
Piazza
The Italian term for a city square. Image courtesy of Phil Gruen
Pier
A massive vertical support often rectangular in plan and therefore differing from a column, sometimes having its own capital and base.  When combined with pilasters, columns, or shafts, it is called a compound pier.  Its proportions are far more variable than a Classical column.  Pier is also the term used for the solid mass between windows, doors, and arches. Image courtesy of Heather Russell
Pilaster
A column is flattened, rectangular shape, projecting slightly form the face of the wall. Image courtesy of Gayle Goudy Kochanski
Plinth
A generally square block forming the bottommost element of a column base; or the projecting lowest portion of a wall. Image courtesy of Gayle Goudy Kochanski
Podium
A massive platform on which an Etruscan, Roman, or other ancient building was sometimes placed. Image courtesy of Gail Gould
Portico
An open, colonnaded, roofed space serving as a porch before the entrance to a building. Image courtesy of Gail Gould
Post and Lintel
A system of construction in which two or more uprights support a horizontal beam; also called trabeated. Image courtesy of Heather Russell
Pronaos
The porch in font of the cella of a Greek or Roman temple formed by the projection of the side walls and a range of columns between the projections. Image courtesy of Gayle Goudy Kochanski
Pylon
In ancient Egyptian architecture, the sloping, tower-like walls flanking the entrance to a temple. Image courtesy of Phil Gruen
Quoin
Large stone or block laid at the corner of a building (or at an opening) used either for reinforcement of the angle or for ornament. Image courtesy of Gail Gould
Revetment
The facing of a surface, usually a wall, with stone for ornamentation or protection.
(Notice how the ornamental revetment is only on the facade and does not continue on the side surfaces.) Image courtesy of Gretchen Ranger
Rib
A slender, projecting arched member of a vault, used to facilitate its construction, reinforce its structure, or articulate its form in varying ways in Roman, Byzantine, and Islamic, Gothic, and Baroque architecture. Image courtesy of Gretchen Ranger
Rib Vault
An arched ceiling or roof supported or reinforced by ribs. Image courtesy of Gretchen Ranger
Rustication
Masonry with massive, strongly textured or rough-hew blocks and sharply sunk joints, distinguished form smooth ashlar. Image courtesy of Phil Gruen
Scotia
A concave molding used as the intermediate part of a base. Image courtesy of Heather Russell
Shaft
The cylindrical body of a column between capital and base. Image courtesy of Heather Russell
Spandrel
The triangular area between adjoining arches, or the triangualr area next to a single arch. Image courtesy of Gayle Goudy Kochanski
Spire
A tall pointed termination of a tower or roof. Image courtesy of Gretchen Ranger
Splay
The widening of windows, doorways, and other openings by slanting the sides.
Springing
The point from which an arch or vault springs or rises from its supports. Image courtesy of Gayle Goudy Kochanski
Squinch
A small arch, or sometimes a lintel, thrown across the angle of a square or polygon to make them more nearly round and thus able to recieve the circular base of a dome. Image courtesy of Gail Gould
Stringcourse
A continuous, projecting horizontal course of masonry, ususally molded, running along, the surface of a wall, to mark an architectural subdivision. Image courtesy of Gayle Goudy Kochanski
Stylobate
The continuous platform of masonry on which a colonnade rests; the uppermost level of the stepped base (crepidoma) of a Greek temple. Image courtesy of Heather Russell
Thrust
The outward force exerted by an arch or vault. Image courtesy of Gayle Goudy Kochanski
Torus
A large convex molding found principally at the base of a column. Image courtesy of Heather Russell
Trabeated
An architectural system using a horizontal beam over supports, as opposed to an arched or arcuated system; synonymous with post and lintel. Image courtesy of Heather Russell
Tracery
Ornamental intersecting stonework in Gothic windows, panels, and screen of Gothic buildings; also used on the surface of late Gothic vaults.  Varied techniques and patterns are given names such as plate tracery (built up in corsed layers like the framing walls), bar tracery (constructed of complex fragments of the total pattern), flowing tracery (seemingly freehand, curvilinear design, though compass drawn), etc. Image courtesy of Gail Gould
Transept
In a basilican church, the arm that crosses the nave at right angles, usually separating it from the apse; twin transept arms may also project from the nave without interrupting it.
Triforium
An arcaded wall passage in a Gothic nave wall, between the clerestory and the main arcade in a three-story elevation; in a four-story elevation, it appears between the gallery and the clerstory. Image courtesy of Gail Gould
Triglyph
In a Doric frieze, the projecting block marked by vertical grooves (glyphs) between the rectangular areas known as metopes Image courtesy of Heather Russell
Vault
An arched ceiling or roof made of stone, brick, or concrete (cf. barrel vault, fan vault). Image courtesy of Heather Russell
Volute
Ornament in the form of a spiral scroll, and the principal feature of the Ionic capital. Image courtesy of Gayle Goudy Kochanski
Voussoir
A wedge-shaped stone used in the construction of an arch or vault. Image courtesy of Gayle Goudy Kochanski
Westwork
In a Carolingian or Romanesque church, the towerlike west end, often containing an entrance vestibule surmounted by a large room open to the nave. Image courtesy of Gail Gould