whetstone
From Longman Dictionary of Contemporary EnglishRelated topics: Toolswhetstonewhet‧stone /ˈwetstəʊn $ -stoʊn/ noun [countable] TZa stone used to make the blade of cutting tools sharpExamples from the Corpuswhetstone• His brain seemed to seize up when Naseby was around, whereas Stitch sharpened it, like a whetstone.• Hereabouts can be found, in quarry spoil, the fine-grained whetstone once transported for use in steel manufacture.• He w as filing arrow heads, and the sound of the metal on the whetstone set Burun's teeth on edge.