whetstone

noun2

1. •
   A sharpening stone; a hard stone or piece of synthetically bonded hard minerals that has been formed with at least one flat surface, used to sharpen or hone an edged tool.

   • […]for alwaies the dulnesse of the foole, is the whetstone of the wits. — 1598
2. •
   (figurative) A stimulant.

verb1

1. •
   To sharpen with a whetstone.

noun1

1. •
   A single instruction of the Whetstone benchmark, often expressed as a value per second.

   • The Prodigy 4 does 500,000 Whetstones. — 1994