Cases of word usage

1) an ornament with a pin for fastening on clothes (brooch)

2) a pin or peg used to keep two pieces of wood etc together (dowel)

3) a wooden or metal pin or bolt, used to fasten parts of woodwork together (peg)

4) a central pin or point on which something turns; something on which an argument or discussion depends (pivot)

5) a metal pin for fixing metal plates (e.g. in a ship's sides), the end being hammered flat to prevent slipping (rivet)

6) forming the main part; a main part or product for trading; a U-shaped metal pin hammered into a surface, used to hold something in position; a piece of wire as pushed through sheets of paper and bent to hold them together (staple)