equine vs wild horse

equine

noun
  • Any horse or horse-like animal, especially one of the genus Equus. 

adj
  • Of or relating to any member or members of the genus Equus. 

  • Of or relating to a horse or horses. 

wild horse

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

  • A feral horse. 

  • An untamed horse. 

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