A chisel is a tool with a flat, sharpened end used to remove material from wood, metal or stone. The sharpened edge is typically made from a hard metal.
Chisels can be used by hitting the non-sharpened end with a mallet or they might be pressed against a spinning piece of wood or metal such as might be found on a lathe or pole lathe.
Medieval chisels can be seen on manuscript images from very early in history and the pole lathe was known from at least the Viking Age. Chisels for lathes have longer handles than ones that are struck.
A chisel with a U-shaped blade is called a gouge.