EXAMPLES FROM THE WEB FOR QUOIN
Quoin—a wedge placed under the breech of a gun to fix its elevation.
In great-gun exercise, the order which prepares for adjusting the quoin.
More time was spent at Quoin Hill than at any other locality.
While collecting at Quoin Hill, we used only guns in taking birds.
This was the only time this species was observed in the Quoin Hill area.
This was a common bird at Quoin Hill but was not seen elsewhere by me.
Garcia took a few at Quoin Hill, but I observed the species there only once.
This species was seen 12 miles north of Kalabakan and at Quoin Hill.
Run in the quoin, and, blast the brig, give her a point-blanker!
The level mark on the quoin is to correspond with the end of the bed.
1530s, "a cornerstone," variant spelling of coin (n.); in early use also in other senses of that word, including "a wedge."