SAH Archipedia uses terms from the Getty Art and Architecture Thesaurus (AAT) to categorize and classify metadata for the entries in the database. For more information on the Getty AAT, click here

Click on the icon to view the definition of the selected term.

lapis lazuli (rock)

A granular crystalline rock composed essentially of lazurite and calcite. This is an old name for gem-variety lazurite.

larch (wood)

Wood of the genus Larix, native to cool and sub-Arctic parts of the Northern Hemisphere. Most larch timber is coarse-grained, hard, and heavy, and is used for the construction of telephone poles, mine timbers, and railroad ties.

lath (grounding surface)

The surface, other than masonry, to which plaster is applied; made from various materials, including expanded metal mesh, gypsum board, or other material that will sufficiently bond the plaster.

laths (wood by form)

Thin, narrow, flat pieces of wood used for many purposes, such as in constructing lattices of trellis work, Venetian blinds, or to form a groundwork upon which to fasten the slates or tiles of a roof or the plaster of a wall or ceiling. For groundwork of any material upon which plaster or another such material is applied, use "lath (grounding surface)."


Secondary roof support members, usually light poles or trimmed saplings, placed perpendicularly or in a herringbone pattern over vigas (primary beams) in Native American or Spanish American adobe construction.

lauan (wood)

Wood obtained from any of several species of the genus Shorea; sold as Philippine mahogany on the American market. It is a reddish- brown wood resembling mahogany in texture, weight, and strength, but it is not dimensionally stable with changes in relative humidity. Lauan wood is used for furniture, cabinetry, veneers, and boat building.

laurel (wood)

Wood of trees belonging to the genus Laurus, native to India, West Pakistan and Burma. It is used extensively for making furniture, cabinet-making, interior joinery, and staircases.

Laurus nobilis (species)

Species of aromatic evergreen tree native to the Mediterranean region but widely cultivated elsewhere, growing 6-18 meters (20-60 feet) in height and having stiff, alternate, oval leaves that are dull and leathery, around 8 cm (3.5 inches) long; the leaf edges are smooth and often wavy, used as a cooking herb. In ancient Greece the wreath of honor placed upon the heads of heroes and winners of games was made from the leaves and branches of this species. The small and inconspicuous flowers are yellowish or greenish white. The fruit is a green, purple, or blackish berry containing a single seed, and when pressed, producing an aromatic oil. The wood is strong and elastic, used for carving and marquetry.


Molten volcanic rock that issues from a volcano or fissure in the earth's surface; also, the same material after being cooled and solidified.

lava rock masonry
No description is available for this term.

lawn (textile)

Sheer, lightweight plain-woven textile, originally of linen now also of fine combed cotton yarn, filled with starch or sizing. often used for handkerchiefs, aprons, and curtains.

lawns (landscaped grass)

Areas of cultivated grass or other ground cover maintained for aesthetic quality or recreation.

lead (metal)

Pure metallic element having symbol Pb and atomic number 82; soft, dense ductile metal of a dull gray color, shiny when freshly cut, occuring naturally most often as a sulfide in the mineral galena. Other lead minerals include anglesite (lead sulfate) and cerussite (lead carbonate). Native metallic lead was found and used from about 3600-2600 BCE when the technique for obtaining lead from roasting the sulfide ore (galena) was discovered. Lead was used to make small cast items such as coins and statuettes, plumbing pipes, spires, statues, cisterns, gargoyles, pigments (lead white, litharge, orange mineral, etc.), as a component in pottery glazes, for roofing, flashing, stained glass windows, as a soft solder, and as radiation shielding.

lead glass

Glass containing a high proportion of lead oxide and having a relatively high refractive index, with poor acid resistance and low rigidity; used in many optical components, neon-sign tubing, and light bulbs.


Visual works or parts of works made from lead, particularly sculptural, ornamental, or architectural objects. Usage may include plumbing or glazier's work.


The skin or hide of an animal that has been tanned to render it resistant to putrefication and relatively soft and flexible when dry. For composite material made from scrap leather pieces, use "maril."

LED bulbs

Lighting devices that incorporate an array of LEDs within a bulb-shaped enclosure, usually made of glass. These are used for general lighting applications, in most cases as a replacement for incandescent light sources, as they offer more efficient energy performance.


A soft coal, usually dark brown, often having a distinct woodlike texture, and intermediate in density and carbon content between peat and bituminous coal.

lime (fruit)

General term for a number of different citrus fruits, both established species and hybrids, that are typically round, green to yellowish green in color, containing acidic pulp that is sweeter than lemons, and of a size usually smaller than lemons.

lime concrete

A concrete made from a mixture of lime, sand, and gravel, widely used before the lime matrix was replaced by portland cement.

lime mortar

A mixture of hydrated lime, sand, and water, which has a compressive strength up to 400 psi.

lime plaster

A type of plaster composed of calcium oxide (lime). Lime plaster has been used since antiquity, prepared by heating limestone to remove carbon dioxide and convert it to anhydrous calcium oxide (quicklime). When quicklime is mixed with water, it converts to calcium hydroxide (slaked lime).


General name for a sedimentary rock existing in many varieties, consisting primarily of calcite or dolomite.


Limonite refers to any hydrated iron ore. A brownish yellow deposit, it is formed by precipitation in marshy areas and is found mixed in clay and sand as loose powder or as a mass. Limonite is also called bog iron ore.

linen (material)

General name for textile woven from the spun fiber of the flax plant.


Durable floor coverings made primarily of linseed oil, with a filler of cork dust or wood flour, and flax, with pigments added to create the desired colors and patterns; also, similar floor coverings made with substitutes for the linseed oil or filler or both.

linter (fiber)

The short downy hairs or fuzz adhering to the cotton seeds (removed by a machine called a linter), which is unsuitable for spinning into yarn and is used as a source of celluloseu. Linter is useful in papermaking and upholstery.

Liriodendron tulipifera (species)

Species of large, columnar tree native to North America, the common name referring to the large flowers that superficially resemble tulips, although the plants are instead closely related to magnolias. They provide food and shelter to butterflies and other animals. They are used for fine-grained, stable timber and landscaping.

live oak (wood)

General term for wood of any species of evergreen oak native to the U.S., often either Quercus virginiana or Q. agrifolia. The light brown wood of live oak trees is strong and hard, once highly valued by shipbuilders. Now the trees are mainly grown as shade trees.

living rock

Refers to rock in its original environment, as opposed to having been quarried. It typically refers to rock that is carved or otherwise used in situ, often to sculpture or architecture carved in situ.

lodgepole pine (wood)

Wood from the Pinus contorta, found in western North America.

log (wood)

The unhewn portion of a felled tree, including a length cut off for use as firewood, construction, or another purpose.

log construction

Vernacular form of construction using entire logs. One of the oldest known methods of construction, log construction has been used for dwellings, as well as churches and bridges. Log walls are produced by stacking logs and filled with mud or other insulating materials. Structures made of logs are characterized by corner joints that interlock with a cross-lap connection, or with dovetailing.

logwood (colorant)

A blackish blue or blood red natural colorant extracted from the logwood tree, Haematoxylon campechianum, of Central America, Mexico, and the West Indies. It was formerly used to make black ink, and is still used to dye textiles black.

longleaf pine (wood)

Wood from the Pinus palustris, found in the southern United States and valued as timber.


Material cut from timber to sizes and forms suitable for structural use.

luster (textile)

Textile made with cotton, silk, or linen warp and wool, mohair, alpaca, or some other glossy hair fiber as weft in order to produce a lustrous surface.

Maclura pomifera (species)

Species of small deciduous tree or large shrub belonging to the mulberry family, Moraceae, typically growing to 8-15 m (26-49 ft) tall. It is dioeceous, with male and female flowers on different plants. The multiple fruit is bumpy and spherical, 7-15 cm in diameter, filled with a sticky white latex sap. In fall, it turns a bright yellow-green color and has a faint odor similar to that of oranges.

magnesian limestone

Limestone containing the combined carbonate of lime and magnesium, and frequently used for building.


White to bluish gray mineral,. It is used in the manufacture of brick and as an ore of magnesium.


Pure metallic element having the symbol Mg and atomic number 12; the lightest metal that is stable under ordinary conditions, silvery white in color. Use also for this metal as processed and formed, usually in combination with other substances, to make various objects and materials.

Magnolia grandiflora (species)

Species of large evergreen tree, reaching over 25 meters in height, native to the southeastern United States, from coastal Virginia south to central Florida, and west to eastern Texas and Oklahoma. It has been widely cultivated with over 100 varieties worldwide, prized for its large dark green leaves and large white fragrant flowers. The wood from the tree is used for furniture, veneer, and other items.

mahogany (wood)

Refers to the wood of trees of the genus Swietenia, found in tropical climates, primarily in Mexico, Cuba, Central America, and the West Indies. It varies in color from yellow to a rich red brown, and is valued in furniture-making and sculpture-carving because it is hard, fine-grained, and takes a high polish. Mahogany has a fine, straight grain that takes a high polish. It is dimensionally stable and does not shrink, warp, or swell. The durable, dark reddish-brown wood was imported to Europe in the 18th century where it became popular for furniture, paneling and veneer. Ammonia brings out a rich, red color in mahogany wood. Mahogany is frequently attacked by pinhole borer beetles. Many woods of similar colors have also been called mahoganies, but usually do not have rich color or fine cutting characteristics of the true mahogany wood. However, the related African genus Khaya produces a similar wood. Mahogany was used by Chippendale, Hepplewhite, and the Adam brothers for high quality furniture.

makore (wood)

Acidic wood of the species Tieghemella heckelii, reddish to purplish-brown in color, typically with straight grain and dark streaks. It is used for furniture, cabinet work, joinery, decorative veneers, panelling, boat building, flooring, turnery, carving, pianos, and other musical instruments.

man-made hydrographic features

Features that contain water and are man-made rather than natural.


Pure metallic element having symbol Mn and atomic number 25; hard, brittle, silvery metal. Use also for this metal as processed and formed, usually in combination with other substances, to make various objects and materials.

Mankato stone

A compact, semi-crystalline magnesian limestone from Minnesota, ranging in color from buff, cream, yellow, gray, pink, or reddish buff. It is commonly used for building as well as for decoration.

maple (wood)

Wood of trees belonging to the genus Acer, light reddish brown in color, with small pores, distinct rings, and rays that show as fine dashes in quarter sawed wood. Maple wood is used for fine furniture, cabinetry, flooring, shoe lasts, and musical instruments.

No description is available for this term.

marble (rock)

A metamorphic, hard, dense, crystalline stone primarily composed of calcium carbonate; it is limestone or dolomite that has been metamorphosed with heat and pressure. Pure calcite marble is white, but impurities produce a wide variety of coloring and patterns. It is finely grained and polishes to a smooth, high gloss. It is used primarily for statuary and buildings. Marble has been quarried from sites around the world since at least the 7th century BCE. The term can also refer more broadly to any crystallized carbonate rock, including true marble and certain types of limestone, that will take a polish and can be used for architectural and ornamental purposes.


Calcareous clay containing up to 40% calcium carbonate.


Cantilevered or suspended roofs over the entrances to buildings, of metal or metal and glass; in the 19th and 20th centuries, common over the entrances to theaters, casinos, and hotels to advertise entertainment. For smaller, often ornamental, rooflike structures at entrances, use "canopies (structural elements)."

Mars brown (color)

A range of brownish colors resembling the color of the synthetic iron oxide pigment known as "Mars brown."

Masonite (TM)

A registered trademark for a type of hardboard building material first made in 1924 by William H. Mason. Masonite is a wet process fiberboard composed of fine wood fibers compressed into a dense, rigid sheet with heat. The fibers are held together by the natural binders from the pulp with no additional adhesive. Masonite boards do not bend or warp easily but the sheets are brittle and break under pressure.

masonry (building materials)

Building materials comprising cut, carved, shaped, or molded units of stone, ceramic brick or tile, concrete, glass, adobe, or other similar material.

masonry units

Refers generally to any naturally occurring or manufactured building units composed of concrete, glass, stone, or other material.

mastic (resin)

Gum exudation of small evergreens native to the Mediterranean countries, soluble in both alcohol and turpentine; used for artists' paint and coating lacquer. Mastic varnish becomes yellow and brittle with age. Mastic was used in 16th and 17th century recipes for oil-resin varnishes; in the 19th century, mastic was a popular clear, glossy spirit varnish for oil paintings and was also used as an additive in oil medium. By the 20th century, its use was superseded by dammar.

matting (roofing material)

Roof covering composed of woven material such as coir, bast, hemp, or grass.


Large open tracts of grassland, sometimes used for pasture.

medium-density fiberboard

Fiberboard that is typically made of wood fibers that are acquired by breaking down scrap remnants of hardwood or softwood; distinguished from low-density fiberboard and high-density fiberboard by density of fiber and strength.


Material in the form of a thin soft pliable sheet or layer.


Material in the form of threads or cords that surround the interstices of a net, netting, screen, or sieve, including any woven, knitted, or knotted material with an open texture and evenly spaced holes, including textiles and interlocking metal links. The size of a net or screen may refer to the spaces rather than to the threads that bound the spaces, for example, indicated by the number of openings per inch or another linear unit.


Any of a large group of substances that typically show a characteristic luster, are good conductors of electricity and heat, are opaque, can be fused, and are usually malleable or ductile.

metal panels
No description is available for this term.

metallic paint

Paint in which the pigment is a metal.

metalwork (visual works)

Visual works that are the products of working any kind of metal, particularly metal objects of artistic merit.

metamorphic rock

Rocks that result from the alteration of pre-existing rocks in response to changing environmental conditions, such as variations in temperature, pressure, and mechanical stress, and the addition or subtraction of chemical components. The pre-existing rocks may be igneous, sedimentary, or other metamorphic rocks.

mica (mineral)

Group of monoclinic minerals with perfect basal cleavage.

micaceous sandstone

Sandstone containing mica.

Milford granite

A coarse biotite granite, quarried in Milford, Massachusetts, composed mostly of light pink feldspar with additions of gray quartz and dark, greenish-black flecks of a chloritic black mica. It is very strong, takes a high polish, and has a fine and close texture, making it one of the most desirable granites quarried in the U.S. for general building as well as decorative purposes.


Planed and patterned lumber for finish work in buildings, including items such as sash, doors, cornices, panelwork, and other items of interior or exterior trim. Does not include flooring, ceiling, or siding.


Naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties; use also for synthetically derived equivalents.

mineral oil

A colorless, aliphatic hydrocarbon oil obtained from petroleum distilled at 330-360 degrees C.

modular brick

Bricks which can be laid to modular dimensions; bricks sized so that the brick plus the mortar joint will form a 4, 8 or 12 inch increment, or module.


Long, lustrous hair of the Angora goat, valued for its strength and excellent spinning qualities.

moist conifer and evergreen broad-leaved forests

Temperate forests of conifer and evergreen broad-leaved trees, located in areas having wet winters and dry summers; rainfall is concentrated in the winter months and winters are relatively mild.

molded brick

Brick molded to a selected shape before firing and subsequently used to make ornamental architectural details.

molding plaster

Calcined gypsum ground fine fine so as to bring out dteails ornamental trim, cornices, and cast work.

Monel (TM)

Alloy composed of about 67% nickel, 28% copper, and 5% other elements such as iron.

monkeypod (wood)

Wood of the species Samanea saman, of the legume family.


Refers to a single large block of stone shaped into a pillar, column, sculpture or other item. For modern structural elements composed of cast concrete, use "concrete monolith."

monumental stone

Stone, generally of impressive bulk or size, used for erecting any variety of monument, but particularly for tombs or tombstones. The term can also refer to stone used to carve monumental statuary or for constructing monumental architecture.

mortar (filler)

A pasty building material that sets to form a hard, infusible solid. Most mortars are mixtures of lime, plaster of Paris, or cement with sand and water. It is used to fill the joints of brick and stone masonry and for other purposes.

mortise-and-tenon joints

Joints made when connecting two pieces of wood where a projecting tongue (tenon) of one piece is made to fit into the corresponding cutout (mortise) in the other piece.

mosaic (process)

A method of decorating surfaces with patterns or pictures composed of small, regularly-shaped pieces of colored durable material, such as stone or glass.

mosaic glass

Glass made with slices of colored canes which can be used as inlays for walls and furniture, fashioned into beads and various kinds of jewelry, or arranged in molds and fused together to form vessels. Distinguished from "millefiori glass" which is glass made with slices of colored canes embedded in clear molten glass, usually creating flowerlike designs.

mosaics (visual works)

Images or patterns composed of small, regularly shaped pieces of durable material, usually stone or colored glass. Distinguished from "opus sectile," which is composed of individually shaped pieces of durable material, usually stone or glass, which conform to the design or pattern.

mother of pearl

Hard, pearly, iridescent internal layer of various kinds of mollusk shell, extensively used for making small articles and inlays.


Soil containing so much water that it is soft and at least semi-fluid.

mud mortar

Building material used for joining elements that is composed of an earth and water mixture. Mud mortar is prone to erosion, and is most effective in warm, dry climates.


A mixture of various formulations used in vernacular architecture as a wall finish.


Slender, vertical, usually nonstructural bars or piers forming a division between doors, screens, or lights of windows; for the small members that divide glazing areas and support the panes or the verticals that separate the panels in panel doors, use "muntins."

mural painting (image-making)

The activity of composing and executing painted decorations or scenes that dominate a wall or ceiling surface.

mural paintings (visual works)

Painted decorations or scenes that dominate a wall (or ceiling) surface. For works in other media that dominate a wall (or ceiling), use the more general term "murals (any medium)".

murals (general, decorations on wall)

Refers to decorations in any medium that dominate a wall (or ceiling) surface; most often refers to works executed on the wall, but may also refer to works done separately and affixed to the wall. For paintings specifically, see "mural paintings."

muscovite (mica)

A colorless or pale brown mica; it has superior dielectric properties and is valued for radio capacitators.

Myrtales (order)

Order of flowering plants composed of 14 families, 380 genera, and about 11,000 species distributed throughout the tropics and warmer regions of the world.

myrtle (wood)

The wood of evergreen shrubs or small trees of the genus Myrtus.

nails (fasteners)

Slender and usually pointed and headed fasteners designed for impact insertion.

natural cement

Cement produced by taking finely pulverizing calcined argillaceous limestone and heating it to complete decarbonation, which is the process of removing carbon dioxide.