Webster's Revised Unabridged Dictionary · 1913

Equestrian

Equestrian , adjective

[Latin equester, from eques horseman, from equus horse: compare French équestre. See Equine.]

1.
Of or pertaining to horses or horsemen, or to horsemanship; as, equestrian feats, or games.
2.
Being or riding on horseback; mounted; as, an equestrian statue.
An equestrian lady appeared upon the plains. — Spectator
3.
Belonging to, or composed of, the ancient Roman equities or knights; as, the equestrian order. — Burke

Equestrian , noun

One who rides on horseback; a horseman; a rider.