to be unused

• 闲置土地

  unused land

• 闲置资金

  unused capital

• 闲置设备

  unused equipment

• 不让机器闲置在那儿

  don't leave the machine unused over there

• 房间反正闲置着，就辟做阅览室吧。

  That room isn't used anyway. Let's turn it into a reading room.