whetstone

Etymology

From Middle English whestone, whetston, whetesston, from Old English hwetstān, from Proto-West Germanic *hwattjastain (“whetstone”). Equivalent to whet (“to sharpen”) + stone.

noun

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.
   It was as if a stone were ground to dust; as if white sparks flew from a livid whetstone, which was his spine; as if the switchback railway, having swooped to the depths, fell, fell, fell. 1922, Virginia Woolf, Jacob's Room, Vintage Classics, paperback edition, page 88-89
2. (computing) A benchmark for evaluating the power and performance of a computer.
3. (figurative) A stimulant.

verb

1. (transitive) To sharpen with a whetstone.