未み成せい線せん

noun

uncompleted railway line

Refers to a railway line that was planned or partially constructed but never finished. Used in historical or planning contexts.

• この未み成せい線せんは、戦せん前ぜんに計けい画かくされたが実じつ現げんしなかった。

  This uncompleted railway line was planned before the war but never realized.