From Longman Dictionary of Contemporary Englishwhetstonewhet‧stone /ˈwetstəʊn $ -stoʊn/ noun [countable] TZa stone used to make the blade of cutting tools sharp
Examples from the Corpus
whetstone• 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. 