equestrian vs troop horse

equestrian

noun
  • One who rides a horse. 

  • Synonym of eques 

adj
  • Of or relating to the ancient Roman class of equites. 

  • Of horseback riding or horseback riders. 

troop horse

noun
  • A cavalry horse. 

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