Whet"stone` (?), n. [AS. hwetstan.]
A piece of stone, natural or artificial, used for whetting, or sharpening, edge tools.
The dullness of the fools is the whetstone of the wits.
Diligence is to the understanding as the whetstone to the razor.
⇒ Some whetstones are used dry, others are moistened with water, or lubricated with oil.
To give the whetstone, to give a premium for extravagance in falsehood. [Obs.]
© Webster 1913.