Clench, to

A landsman would say ‘to rivet’. To draw together two components, usually timber, with a copper Boat-nail. The nail is square in section and its end is spread over a cup-shaped washer called a rove. Clinker-built hulls are built by clenching all the planks together, which is why many people quite logically insist on calling them Clencher-built. Please yourself.