obstacle

obstacle (http://definr.com/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)