Pronunciation: (vān),[key] —adj.,-er, -est. 1. excessively proud of or concerned about one's own appearance, qualities, achievements, etc.; conceited: a vain dandy. 2. proceeding from or showing personal vanity: vain remarks. 3. ineffectual or unsuccessful; futile: a vain effort. 4. without real significance, value, or importance; baseless or worthless: vain pageantry; vain display. 5. Archaic.senseless or foolish.
6. in vain, a. without effect or avail; to no purpose: to apologize in vain. b. in an improper or irreverent manner: to take God's name in vain.