adjective

1. having no real value or significance; worthless, empty, idle, hollow, etc. vain pomp
2. without force or effect; futile, fruitless, unprofitable, unavailing, etc. a vain endeavor
3. having or showing an excessively high regard for one's self, looks, possessions, ability, etc.; indulging in or resulting from personal vanity; conceited
4. Archaic lacking in sense; foolish

Etymology: OFr < L vanus, empty, vain: see want