vain /ˈven/
  (a.)徒勞的,徒然的,無效的,空虛的,自負的
  Vain a. [Compar. Vainer superl. Vainest.]
  1. Having no real substance, value, or importance; empty; void; worthless; unsatisfying. “Thy vain excuse.”
     Every man walketh in a vain show.   --Ps. xxxix. 6.
     Let no man deceive you with vain words.   --Eph. v. 6.
     Vain pomp, and glory of this world, I hate ye!   --Shak.
     Vain wisdom all, and false philosophy.   --Milton.
  2. Destitute of force or efficacy; effecting no purpose; fruitless; ineffectual; as, vain toil; a vain attempt.
     Bring no more vain oblations.   --Isa. i. 13.
  Vain is the force of man
  To crush the pillars which the pile sustain.   --Dryden.
  3. Proud of petty things, or of trifling attainments; having a high opinion of one's own accomplishments with slight reason; conceited; puffed up; inflated.
     But wilt thou know, O vain man, that faith apart from works is barren?   --James ii. 20 (Rev. Ver.).
  The minstrels played on every side,
  Vain of their art.   --Dryden.
  4. Showy; ostentatious.
     Load some vain church with old theatric state.   --Pope.
  Syn: -- Empty; worthless; fruitless; ineffectual; idle; unreal; shadowy; showy; ostentatious; light; inconstant; deceitful; delusive; unimportant; trifling.
  Vain, n. Vanity; emptiness; -- now used only in the phrase in vain.
  For vain. See In vain. [Obs.] --Shak.
  In vain, to no purpose; without effect; ineffectually. “ In vain doth valor bleed.” --Milton. “ In vain they do worship me.” --Matt. xv. 9.
  To take the name of God in vain, to use the name of God with levity or profaneness.
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  vain
       adj 1: characteristic of false pride; having an exaggerated sense
              of self-importance; "a conceited fool"; "an attitude
              of self-conceited arrogance"; "an egotistical
              disregard of others"; "so swollen by victory that he
              was unfit for normal duty"; "growing ever more
              swollen-headed and arbitrary"; "vain about her
              clothes" [syn: conceited, egotistic, egotistical,
               self-conceited, swollen, swollen-headed]
       2: unproductive of success; "a fruitless search"; "futile years
          after her artistic peak"; "a sleeveless errand"; "a vain
          attempt" [syn: bootless, fruitless, futile, sleeveless]