Definition of "equestrian"

equestrian

adjective
comparative more equestrian, superlative most equestrian
1. Of horseback riding or horseback riders.
  Quotations
  The society of colonial Spanish-America was one of the most equestrian in all history, and, to a very great extent, its existence depended on the adaptability of the Old World horse to New World conditions.
  1973, Alfred W. Crosby, The Columbian Exchange, Westport, Conn.: Greenwood Press, page 82
2. (historical) Of or relating to the ancient Roman class of equites.
noun
plural equestrians
1. One who rides a horse.
2. (historical) Synonym of eques