n.
Pronunciation: ' ko ̇ in, ' kwo ̇ in
Function: noun
Etymology: alteration of 1 coin
Date: 1532
1 a : a solid exterior angle (as of a building) b : one of the members (as a block) forming a quoin and usually differentiated from the adjoining walls by material, texture, color, size, or projection
2 : the keystone or a voussoir of an arch
3 : a wooden or expandable metal block used by printers to lock up a form within a chase
quoin 1b