Answer: quoin

AnswerCrossword Clue
QUOINCornerstone
QUOINWedge of stone.
QUOINWedgelike piece of stone
QUOINKeystone
quoina solid exterior angle (as of a building)
quointo wedge (to force apart with wood or metal)
quoinwooden or expandable metal block used by printers to lock up a form within a chase
quoinone of the stones forming an external wall; cornerstone.
quoinexternal solid angle
quoincornerstone