mare vs mustang

mare

noun
  • An adult female horse. 

  • On Saturn's moon Titan, any of several lakes which are large expanses of what is thought to be liquid hydrocarbons. 

  • A nightmare; a frustrating or terrible experience. 

  • A foolish woman. 

  • A large, dark plain, which may have the appearance of a sea. 

mustang

noun
  • A small, hardy, naturalized (feral) horse of the North American west. 

  • A merchant marine who joined the U.S. Navy as a commissioned officer during the American Civil War. 

  • A commissioned officer who started military service as an enlisted person. 

verb
  • To hunt mustangs (wild horses), either for military use or for slaughter as pet food. 

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