[noun] the state or condition of being obstructed Synonyms: blockage
[noun] 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" Synonyms: obstacle
[noun] the act of obstructing; "obstruction of justice"