mortar

mortar¹

/mawr"teuhr/, n.

1. a receptacle of hard material, having a bowl-shaped cavity in which substances are reduced to powder with a pestle.

2. any of various mechanical appliances in which substances are pounded or ground.

3. a cannon very short in proportion to its bore, for throwing shells at high angles.

4. some similar contrivance, as for throwing pyrotechnic bombs or a lifeline.

v.t., v.i.

5. to attack with mortar fire or shells.

[bef. 1000; ME, OE mortere and OF mortier < L mortarium; in defs. 3, 4 trans. of F mortier < L, as above; see -AR²]

mortar²

—mortarless, adj. —mortary, adj.

/mawr"teuhr/, n.

1. a mixture of lime or cement or a combination of both with sand and water, used as a bonding agent between bricks, stones, etc.

2. any of various materials or compounds for bonding together bricks, stones, etc.: Bitumen was used as a mortar.

v.t.

3. to plaster or fix with mortar.

[1250-1300; ME morter < AF; OF mortier MORTAR¹, hence the mixture produced in it]

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I

Material used in building construction to bond brick, stone, tile, or concrete blocks into a structure.

The ancient Romans are credited with its invention. Mortar consists of sand mixed with cement and water. The resulting substance must be sufficiently flexible to flow slightly but not collapse under the weight of the masonry units. Before the 19th-century invention of portland cement, masons used thin joints of lime mortar, which required greater precision than the thicker joints of portland-cement mortar and were not as strong. For tilework, a very thin mortar called grout is used. Pointing is the process of finishing a masonry joint.

II

Short-range artillery piece with a short barrel and low muzzle velocity that fires an explosive projectile in a high-arched trajectory.

Large mortars were used against fortifications and in siege operations from medieval times through World War I. Since 1915, small portable models have been standard infantry weapons, especially for mountain or trench warfare. Medium mortars, with a caliber of about 3–4 in. (70–90 mm), a range of up to about 2.5 mi (4 km), and a bomb weight of up to 11 lbs (5 kg), are now widely used.

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▪ building material

      in technology, material used in building construction to bond brick, stone, tile, or concrete blocks into a structure. Mortar consists of inert siliceous (sandy) material mixed with cement and water in such proportions that the resulting substance will be sufficiently plastic to enable ready application with the mason's trowel and to flow slightly but not collapse under the weight of the masonry units. Slaked lime is often added to promote smoothness, and sometimes colouring agents are also added. cement is the most costly ingredient and is held to the minimum consistent with desired strength and watertightness.

      Mortar hardens into a stonelike mass and, properly applied, distributes the load of the structure uniformly over the bonding surfaces and provides a weathertight joint.

▪ weapon

      in military science, short-range artillery piece with a short barrel and low muzzle velocity, firing an explosive projectile in a high-arched trajectory. Large types were used against fortifications and in siege operations from medieval times through World War I. Since 1915, small, portable models have become standard infantry weapons, especially for trench or mountain warfare. Medium mortars, with a calibre of 70–90 mm (about 3–4 inches), a range up to 4,000 m (about 2.5 miles), and a bomb weight of up to 5 kg (11 pounds), are now favoured.

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