rapidity vs scutter

rapidity

noun
  • speed, swiftness; the condition of being rapid 

  • A measure of the velocity of a particle in a beam relative to the beam's axis 

  • A measure of velocity relative to the speed of light 

scutter

noun
  • A hasty run. 

  • Thin excrement. 

verb
  • To run with a light pattering noise; to skitter. 

  • To void thin excrement. 

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