The term 'MAKE A TUNNEL' can be solved by the word 'BORE', which is a four-letter word. Boring is a process used to create tunnels, shafts, and other underground passageways. It involves drilling a hole through rock or soil using a drill bit, and then removing the material that has been drilled out. Boring is often used in mining operations, as well as for creating tunnels for transportation and utility purposes.