fu·til·i·ty /fjʊˈtɪləti/
  無用,無益,無價值
  Fu·til·i·ty n.
  1. The quality of being talkative; talkativeness; loquaciousness; loquacity. [Obs.]
  2. The quality of producing no valuable effect, or of coming to nothing; uselessness.
     The futility of this mode of philosophizing.   --Whewell.
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  futility
       n : uselessness as a consequence of having no practical result