quoin

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. An exterior angle of a wall or other piece of masonry.
2. n. Any of the stones used in forming such an angle, often being of large size and dressed or arranged so as to form a decorative contrast with the adjoining walls.
3. n. A keystone.
4. n. Printing A wedge-shaped block used to lock type in a chase.
5. n. A wedge used to raise the level of a gun.
6. v. To provide, secure, or raise with a quoin or quoins.

Century Dictionary and Cyclopedia

1. n. An external solid angle; specifically, in architecture and masonry, the external angle of a building. The word is generally applied to the separate stones or blocks of which the angle is formed; when these project beyond the general surface of the walls, and have their corners chamfered off, they are called rustic quoins or bossage.
2. n. A wedge-like piece of stone, wood, metal, or other material, used for various purposes. In masonry, a wedge to support and steady a stone.
3. n. In gem-cutting, any one of the four facets on the crown of a brilliant; also, any one of the four facets on the pavilion or base. These facets divide each portion of the brilliant into four parts. Also called lozenge. See cut under brilliant.
4. n. Nautical, a wedge placed beneath a cask when stowed on shipboard, to prevent it from rolling.
5. n. In gunnery, a wooden wedge used to hold a gun at a desired elevation.
6. To wedge, steady, or raise with quoins, as a stone in building a wall, the types in a chase, etc.: generally with up. See quoin, n., 2.
7. n. The solid angle of a crystal in which three or more faces meet. Also written coign.

Wiktionary

1. n. Any of the corner building blocks of a building, usually larger or more ornate than the surrounding blocks.
2. n. The keystone of an arch.

GNU Webster's 1913

1. n. Originally, a solid exterior angle, as of a building; now, commonly, one of the selected pieces of material by which the corner is marked.
2. n. A wedgelike piece of stone, wood, metal, or other material, used for various purposes
3. n. To support and steady a stone.
4. n. To support the breech of a cannon.
5. n. To wedge or lock up a form within a chase.
6. n. To prevent casks from rolling.

WordNet 3.0

1. n. expandable metal or wooden wedge used by printers to lock up a form within a chase
2. n. the keystone of an arch
3. n. (architecture) solid exterior angle of a building; especially one formed by a cornerstone