bondstone
/ˈbɑndˌstoʊn/
noun
- A stone used in masonry to tie or bond two walls or sections together, often by extending through the thickness of a wall.
- The mason placed a bondstone across the corner to strengthen the joint.
- Without enough bondstones, the wall might crack under pressure.
- Old stone buildings often use long bondstones to connect the inner and outer layers of the wall.