lathekin

noun1

1. •
   A tool used by glaziers making leaded windows and other stained glass items. It is a short piece of wood or plastic straight on one edge, with the other side indented or rounded. It is used for such purposes as applying metal to the edges of glass or cleaning excess cement.

   • The lathekin, the most ancient tool of the glazier, is simply a piece of hard wood-box, lance, or ebony-cut to the shape shown, for opening, pressing and regulating the leads. — 1902