The term Cumberland GAP refers to a mountain pass located in the Appalachian Mountains between Kentucky, Virginia, and Tennessee. It was an important route for settlers moving westward in the 18th and 19th centuries. The two crossword solutions for this term are GAP (3 letters) and BOONE (5 letters). GAP is a reference to the mountain pass itself, while BOONE is a reference to Daniel Boone, the famous American frontiersman who explored and helped settle the area around the Cumberland GAP.