The two upright standing stones which are placed either side of the recumbent stone in some Scottish stone circles.
The two stones which adjoin the prostrate stone in a recumbent stone circle. The flankers are often the tallest stones in the circle
Application in which circle top window is placed along the side (flanked with) straight glass windows on each side. The circle top is covered with an arch and the side straight glass windows are flanked with crossheads.