Definitions:

1. In a way that is futile, unsuccessful, or ineffective. ADVERB
   • He searched vainly for a way out of the maze.
2. In a way that shows excessive pride in one's appearance or achievements. ADVERB
   • He glanced vainly at his reflection in every window.

Synonyms:

• conceitedly
• fruitlessly
• in vain
• proudly
• self-admiringly
• to no avail