ob·sta·cle /ˈɑbstɪkəl, ˌstɪ-/
  障礙,障礙物,妨礙,阻礙
  Ob·sta·cle n.  That which stands in the way, or opposes; anything that hinders progress; a hindrance; an obstruction, physical or moral.
  If all obstacles were cut away.
  And that my path were even to the crown.   --Shak.
  Syn: -- Impediment; obstuction; hindrance; difficulty. See Impediment, and Obstruction.
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  obstacle
       n 1: something immaterial that stands in the way and must be
            circumvented or surmounted; "lack of immagination is an
            obstacle to one's advancement"; "the poverty of a
            district is an obstacle to good education"; "the
            filibuster was a major obstruction to the success of
            their plan" [syn: obstruction]
       2: an obstruction that stands in the way (and must be removed
          or surmounted or circumvented)