The term 'PART OF DRILL' can be solved by the three-letter word 'BIT'. A BIT is a cutting tool used in a drill to bore holes into materials such as wood, metal, and plastic. It is usually made of steel or tungsten carbide and is attached to the end of a drill shaft. Bits come in various shapes and sizes and are designed for specific tasks. They are also used in other tools such as routers and lathes.