What does the word Welding mean?

In the Check Point portion of the Trouble Shooting Section in the YAMAWA General Catalog , the term "Welding" is used to describe what happens when the workpiece material is heated to a point of melting while threading. The melted material adheres, "Welds" to the tap or Die and Solidifies. As welding develops, various
tapping problems will occur, so be careful.