noun
side platform; marginal platform
Railway term for a platform that faces only one side of the track, typically used in pairs on opposite sides of the tracks.
この駅は相対式ホームで、上下線の乗り場が向かい合っている。
This station has side platforms, with the inbound and outbound platforms facing each other.
An island platform serves both sides of a single platform, whereas a side platform serves only one side.
Compound of 相対 (sōtai, 'facing each other') + 式 (shiki, 'style') + ホーム (hōmu, from English 'platform').