Definition of vain

• superl. - Having no real substance, value, or importance; empty; void; worthless; unsatisfying.
• superl. - Destitute of forge or efficacy; effecting no purpose; fruitless; ineffectual; as, vain toil; a vain attempt.
• superl. - Proud of petty things, or of trifling attainments; having a high opinion of one's own accomplishments with slight reason; conceited; puffed up; inflated.
• superl. - Showy; ostentatious.
• n. - Vanity; emptiness; -- now used only in the phrase in vain.