騎手【きしゅ】
horseman, rider, jockey
一騎打ち【いっきうち】
personal combat, one-to-one fight
騎馬【きば】
horse riding, horseback riding, horseback rider
騎士【きし】
(medieval) knight, samurai on horseback
騎乗【きじょう】
riding (on horseback), mounting (a horse)
騎士道【きしどう】
chivalry
騎兵【きへい】
cavalry, cavalryman, trooper