The term 'USE A WHETSTONE' refers to a process of honing, grinding, and sharpening an object. HONE is a four-letter word meaning to make more acute or effective, usually by polishing or refining. GRIND is a five-letter word meaning to reduce to small particles or powder by friction. SHARPEN is a seven-letter word meaning to make or become sharp or sharper. Using a whetstone is a process of honing, grinding, and sharpening an object to make it more effective.