polearm vs tusker

polearm

noun
  • A close-quarter combat weapon with the main fighting part of the weapon placed on the end of a long shaft, typically of wood. 

tusker

noun
  • A tool used in peat cutting, a type of spade similar to a cascrom. 

  • An animal, such as a bull elephant or a boar, with large tusks. 

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