noun, noun which may take the genitive case particle 'no'
horseback riding; mounted
Refers to riding a horse or being on horseback. Often used attributively (騎馬の) to describe things related to mounted activity, such as 騎馬隊 (mounted troops) or 騎馬戦 (cavalry battle). The gloss 'horseback rider' is a contextual extension, not a separate sense.
He galloped across the plain on horseback.
Mounted police officers led the parade.
The samurai headed to the battlefield on horseback.
The mounted warriors formed a line.
騎馬 describes being mounted on a horse (e.g. a horseman or mounted troops), whereas 騎乗 is the action of mounting and riding, so learners can confuse the state with the act.
Used for mounted horsemen; in practice this is mostly a formal/literary counter.
Compound of 騎 (riding on horseback) and 馬 (horse). The reading きば is the on'yomi for both characters.