1. excessively proud of or concerned about one's own appearance, qualities, achievements, etc.; conceited: a vain dandy.
2. proceeding from or showing pride in or concern about one's appearance, qualities, etc.; resulting from or displaying vanity.
He made some vain remarks about his accomplishments.
3. ineffectual or unsuccessful; futile: vain hopes; a vain effort; a vain war.
without real significance, value, or importance; baseless or worthless: vain pageantry; vain display.
Archaic. senseless or foolish.