介绍： If you something in vain, you do not succeed in achieving what you intend.
-He stopped at the door, waiting in vain for her to acknowledge his presence.

If you say that something such as someone's death, suffering, or effort was in vain. you mean that if was useless because it did not achieve anything.
-He w...

介绍： If you something in vain, you do not succeed in achieving what you intend.
-He stopped at the door, waiting in vain for her to acknowledge his presence.

If you say that something such as someone's death, suffering, or effort was in vain. you mean that if was useless because it did not achieve anything.
-He wants the world to know his son did not die in vain.