- quoin, coign, coigne - expandable metal or wooden wedge used by printers to lock up a form within a chase
--1 is a kind of wedge
- quoin, coign, coigne - the keystone of an arch
--2 is a kind of keystone, key, headstone
- corner, quoin - (architecture) solid exterior angle of a building; especially one formed by a cornerstone
--3 is a kind of structure, construction
--3 is a part of building, edifice