Definitions
1.AdjectiveOverly proud of oneself, especially concerning appearance; having a high opinion of one's own accomplishments with slight reason.
2.AdjectiveHaving no real substance, value, or importance; empty; void; worthless; unsatisfying.
3.AdjectiveEffecting no purpose; pointless, futile."vain toil a vain attempt"
4.AdjectiveShowy; ostentatious.
5.VerbTo frustrate. (The addition of quotations indicative of this usage is being sought:)