chopping vs colter

chopping

noun
  • The action by which something is chopped. 

adj
  • Shifting or changing suddenly, as the wind; also, having tumbling waves dashing against each other. 

colter

noun
  • A knife or cutter attached to the beam of a plow to cut the sward, in advance of the plowshare and moldboard. 

  • The part of a seed drill that makes the furrow for the seed. 

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