KJV Dictionary Definition: vainly
1. Without effect; to no purpose; ineffectually; in vain.
In weak complaints you vainly waste your breath.
2. Boastingly; with vaunting; proudly; arrogantly.
Humility teaches us not to think vainly nor vauntingly of ourselves.
3. Idly; foolishly.
Nor vainly hope to be invulnerable.