quoin noun. [kɔɪn] Also (earlier) coin. ME.
[Var. of COIN noun: cf. COIGN noun.]
1. An external angle of a wall or building; any of the stones or bricks forming this angle, a cornerstone. ME.

2. a. A wedge for keeping a thing securely in position; spec. (a) Printing either of a pair of wooden wedges for locking up a forme of type; a metal device operated by a key performing a similar function; (b) Nautical a wedge for preventing casks, cannons, etc. from rolling freely on a ship. L16.
b. A wedge with a handle at the thick end, for adjusting the level of a gun barrel. E17.
c. Any of the wedge-shaped stones of an arch, esp. the keystone. rare. M18.

3. An angle; a wedge-shaped object. M19.
trigonal quoin: see TRIGONAL 1b. trihedral quoin: see TRIHEDRAL adjective.

■ quoining noun stone or brick (for) forming a quoin of a wall or building LME.

[TahlilGaran] English Dictionary ▲

quoin verb trans. [kɔɪn] Also (earlier) coin, coigne. L15.
[from QUOIN noun, partly as var. of coin.]
1. Secure or raise with a quoin or wedge. Also foll. by up. L15.

2. Provide with quoins or corners. E18.

[TahlilGaran] English Dictionary ▲