quoin

IPA: kwɔɪn

Any of the corner building blocks of a building, usually larger or more ornate than the surrounding blocks.
The keystone of an arch.
(printing, historical) A metal wedge which fits into the space between the type and the edge of a chase, and is tightened to fix the metal type in place.
(obsolete, nautical) A form of wedge used to prevent casks from moving
(firearms) A wedge of wood or iron put under the breech of heavy guns or the muzzle of siege-mortars to raise them to the proper level.
(horticulture) A number of apple varieties with a distinctive ribbed appearance, like corners of a coin.

Examples of "quoin" in Sentences

FX: picks up quoin and wanders off to buy a cup of coffee.
The figure 8 represents what is called a quoin, and keeps the bolster in its place.
Or are we leaving it up to the kids to learn on their own while we maintain the status-quoin our classrooms?
The two inner sides of each pair of skill facets form the half of a diamond or lozenge-shaped facet, called a "quoin," of which there are four.
A quoin is a solid which differs from a wedge in having its sharp end formed by the steep inclination of one side, instead of the mutual tapering of both sides.
The letterpress landscape is littered with Qs: quad (short for quadrat), quoin, quarto, quire, question & quotation marks, even quadrata (Roman inscriptional capitals, of which I am particularly fond).