colter vs hunting knife

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. 

hunting knife

noun
  • A large knife designed for use in hunting animals, usually with a smooth front edge and a back edge that is partially serrated for sawing. 

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