hackney vs wild horse

hackney

noun
  • A breed of English horse. 

  • A carriage for hire or a cab. 

  • A horse used to ride or drive. 

verb
  • To make uninteresting or trite by frequent use. 

  • To use as a hackney. 

  • To carry in a hackney coach. 

adj
  • Much used; trite; mean. 

  • Offered for hire. 

wild horse

noun
  • A feral horse. 

  • An untamed horse. 

  • A member of the species Equus ferus, sometimes excluding the domesticated horse. 

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