1) Agent for getting an edge on 2) Sharpener 3) SSharpener 4) Stone 1) Hone 2) Honer 3) Oilstone 
[benchmark] The Whetstone benchmark is a synthetic benchmark for evaluating the performance of computers. It was first written in Algol 60 in 1972 at the National Physical Laboratory in the United Kingdom and derived from statistics on program behaviour gathered on the KDF9 computer, using a modified version of its Whetstone Algol 60 compil...
• (n.) A piece of stone, natural or artificial, used for whetting, or sharpening, edge tools.
Whet'stone` noun [ Anglo-Saxon hwetstān .] 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.» Shak. « Diligence is to the understanding as the whetstone ...
[n] - a flat stone for sharpening edged tools or knives
noun a flat stone for sharpening edged tools or knives