Describes having a high opinion of one’s own abilities, looks, or self-worth. Similar to arrogant.
Example: The girl was so vain. Every time she passed a reflection of herself in the mirror she had to stop and admire it.
(Do something) in vain
Means to not succeed in accomplishing the intended outcome of an action.
Example: The children worked in vain to build a higher wall around their sand castle on the beach. They were too close to the rising water.