a : a tool usually in the form of a short rod of steel that is variously shaped at one end for different operations (such as forming, perforating, embossing, or cutting)
b : a short tapering steel rod for driving the heads of nails below a surface
c : a steel die faced with a letter in relief that is forced into a softer metal to form an intaglio matrix from which foundry type is cast
d : a device or machine for cutting holes or notches (as in paper or cardboard)