Sharpening a blade is the process of making it sharper by removing small amounts of material from its edge. The two crossword solutions for the term 'sharpen, as a blade' are 'STROP' and 'WHET'. STROP is a verb meaning to sharpen a blade on a leather strap or other abrasive surface. WHET is also a verb meaning to sharpen a blade with a whetstone. Both processes involve grinding away small amounts of material from the blade's edge in order to make it sharper.