(vainer, vainest)
1.
A vain attempt or action is one that fails to achieve what was intended.
The drafting committee worked through the night in a vain attempt to finish on schedule...
= fruitless
ADJ: ADJ n
• vainly
He hunted vainly through his pockets for a piece of paper.
ADV: ADV with v
2.
If you describe a hope that something will happen as a vain hope, you mean that there is no chance of it happening.
He married his fourth wife, Susan, in the vain hope that she would improve his health.
ADJ: ADJ n
• vainly
He then set out for Virginia for what he vainly hoped would be a peaceful retirement.
ADV: ADV with v
3.
If you describe someone as vain, you are critical of their extreme pride in their own beauty, intelligence, or other good qualities.
I think he is shallow, vain and untrustworthy.
ADJ [disapproval]
4.
If you do 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...
PHRASE: PHR after v, v-link PHR
5.
If you say that something such as someone's death, suffering, or effort was in vain, you mean that it was useless because it did not achieve anything.
He wants the world to know his son did not die in vain.
PHRASE: PHR after v, v-link PHR