from The Century Dictionary.
- noun A tool used by joiners to hold work to the table, or to secure two pieces together.
Sorry, no etymologies found.
It is set diagonally, so as to expose two faces to the rear; the rear angle chamfered, to afford a bearing for the clamp-screw.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance