angle grinder vs whetstone

angle grinder

noun
  • A usually hand-held grinder which uses a pair of internal gears to place the rotational axis of the grinding or cutting wheel perpendicular to that of the driving motor. 

whetstone

noun
  • 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. 

  • A benchmark for evaluating the power and performance of a computer. 

  • A stimulant. 

verb
  • To sharpen with a whetstone. 

How often have the words angle grinder and whetstone occurred in a corpus of books? (source: Google Ngram Viewer )