grey trout vs mackinaw

grey trout

mackinaw

noun
  • A flat-bottomed cargo boat; mackinaw boat. 

  • A heavy woolen cloth. 

  • A blanket made of wool, formerly distributed to the Amerindians by the U.S. government. 

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