夜や戦せん

noun

night warfare; night battle

Refers to military combat conducted at night. Often used in historical or military contexts.

• 夜や戦せんの訓くん練れんは特とくに難むずかしい。

  Training for night warfare is especially difficult.

• この戦たたかいは夜や戦せんだったため、混こん乱らんが生しょうじた。

  Because this battle was a night battle, confusion arose.