arcade A series of arches supported by columns or piers, either attached to a wall or freestanding. Plaza Mayor, Madrid

Place des Vosges, Paris Examples:

balustrade A railing with supporting balusters (small closely spaced posts). Bourla Theater, Antwerp Example:

barrel vault A ceiling or roof consisting of a continuous semicircular or pointed arch. Also known as a tunnel vault. St. Peter's Basilica, Rome

Basilica da Estrela, Lisbon Examples:

blind arch An arch with no opening. Vrtba Garden, Prague Example:

cantilever A beam or other projection that is unsupported at one end. Falling Water, Mill Run Example:

capital The top part of a column or pillar.

composite order Very similar to the Corinthian order, but here ionic volutes are added to the capital. Pantheon, Rome

US Capitol, Washington DC Examples:

coffer A recessed, usually square or octagonal panel in a ceiling, often used to lighten the weight of a dome. Pantheon, Rome

Union Station, Washington Examples:

corbie gable A gable with a series of steplike projections.

corinthian order The most ornate of the classical Greek orders, characterized by a fluted column and a capital decorated with acanthus leaves. Pantheon, Rome

US Capitol, Washington DC Examples:

cornice A molding or ornamentation that projects from the top of a building.

crenelation A wall at the top of a fortified building with regular gaps allowing defenders to shoot from. Also known as battlement. Steen, Antwerp

Bargello, Florence Examples:

cross vault A tunnel or barrel vault intersecting at right angles. Also known as a groin vault; the groin is the line created by the intersection. Seville Cathedral

St. Paul's Church, Antwerp Examples:

dome A vaulted structure with an elliptical plan, usually a cross-section of a sphere, used to distribute an equal thrust in all directions. US Capitol, Washington DC

St. Peter's Basilica, Rome Examples:

doric order The oldest of the five classical orders, characterized by a fluted column with no base and a plain capital. Lincoln Memorial, Washington DC Example:

dormer A window in a small, often gabled structure set vertically on a sloping roof, allowing light to enter the attic. Palacio de Santa Cruz, Madrid Example:

fanlight A semicircular window, usually located above a door.

finial A sculptured ornament fixed to the top of a peak, arch, gable or similar structure.

flemish bond A brickwork bond with alernating headers (short side) and stretchers (long side) in each course (row).

frieze The horizontal part of a classical entablature just below the cornice, often decorated with carvings. Pantheon, Rome

Jefferson Memorial, Washington DC Examples:

gable The triangular section of a wall on the side of a building with a double-pitched roof.

gargoyle A grotesquely carved figure that serves as a spout to carry water from a gutter away from the building. Notre-Dame, Paris

Sacré-Coeur, Paris Examples:

gazebo A freestanding ornamental pavilion - often at the top of a hill in a garden - that provides a view over the area. Jardin des Plantes, Paris Example:

ionic order One of the classical orders characterized by a fluted column, a molded base and a capital decorated with volutes. Palais Garnier, Paris Example:

mascaron An architectural ornament representing a face or head. The head - either from a human or an animal - is often grotesque or frightening. Bridge of Sighs, Venice

New York Public Library Examples:

mudéjar architecture A style of Spanish architecture employed by Muslims after the Christian reconquest. Characterized by a fusion of Islamic with Gothic and Romanesque elements. Arc de Triomf, Barcelona Example:

oriel A projecting bay window on an upper floor.

pagoda A tower structure, often rectangular or octagonal, with projecting roofs at each story. Commonly used as a temple, particularly in Asia. Kew Gardens, London

Japanese Tea Garden, San Francisco Examples:

pilaster A rectangular column with a base, shaft and capital projecting from a wall as an ornamental motif. City Hall, Philadelphia

São Roque Church, Lisbon Examples:

pointed arch An arch with a pointed crown, typically seen in Gothic architecture. Notre-Dame de Paris

Römer, Frankfurt Examples:

portico A roofed porch usually supported by columns, often leading to the entrance of the building. White House, Washington

Pantheon, Rome Examples:

reinforced concrete Concrete containing steel rods or metal netting to increase its tensile strength.

richardsonian romanesque A Romanesque revival style named after the American 19th century architect H.H. Richardson. Characterised by heavy arches and masonry walls. Trinity Church, Boston

Ontario Legislative Building, Toronto Examples:

rose window A circular window, usually found in churches and symmetrically decorated with stained glass. Notre-Dame, Paris

National Cathedral, Washington, DC Examples:

sgraffito A technique used for the decoration of walls, where plaster is scratched to reveal a differently colored pattern beneath. Royal Palace, Dresden Example:

tracery Ornamental, often lacy stonework or timber pattern, in particular the openwork in the upper part of Gothic windows. Notre Dame, Paris

Cathedral of our Lady, Antwerp Examples:

tuscan order A classical order characterized by an unfluted column and a plain base and capital. Union Station, Chicago Example: