The term JOIN A CERTAIN WAY can be solved by the four letter word WELD. Welding is a fabrication process that involves joining two or more materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, forming a permanent bond. It is a common technique used in the construction of buildings, bridges, and other structures, as well as in the manufacturing of products such as automobiles, ships, and aircraft.