mackinaw vs tails

mackinaw

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

  • A flat-bottomed cargo boat; mackinaw boat. 

  • A heavy woolen cloth. 

tails

noun
  • The side of a coin that doesn't bear the picture of the head of state or similar. 

  • Tailings; waste. 

  • Tailings, feints. 

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