The crossword solution for the term 'ROUNDED PIN' is HOB, which is a three-letter word. A HOB is a type of rounded pin that is used to hold two pieces of material together. It is typically made of metal and has a head on one end and a point on the other. The head is usually larger than the point, allowing it to be easily inserted into a hole in the material. Hobs are commonly used in carpentry and metalworking.