1) Masonry binder 
• (n.) A stone running through a wall from one face to another, to bind it together; a binding stone.
Bond'stone` noun [ Bond , noun + stone .] (Masonry) A stone running through a wall from one face to another, to bind it together; a binding stone. 
In masonry, a bondstone is a stone running through a wall from one face to another, to bind it together.
a stone, as a perpend, for bonding facing masonry to a masonry backing.