man and horse; rider and horse
Refers to a human and a horse together, often in contexts of riding, cavalry, or mythological creatures. Commonly seen in the phrase 人馬一体 (unity of rider and horse).
See also: 人馬一体 (じんばいったい)
Rider and horse became one and jumped over the obstacle.
centaur
Mythological creature with the upper body of a human and the lower body of a horse. The cross-reference to ケンタウロス indicates this is the same concept.
See also: ケンタウロス
The centaur that appears in Greek mythology is also called a kentauros.
coming and going of people and horses; passage of people and horses
Compound of 人 (human) and 馬 (horse). The mythological sense is a calque or semantic extension from Western centaur concepts.