1. 路障；障碍（物）
    An obstruction is something that blocks a road or path.

obstruction在线翻译

    e.g. John was irritated by drivers parking near his house and causing an obstruction.
           约翰对那些在他家附近泊车堵住通道的司机感到恼火。

2. （体内的）梗阻
    An obstruction is something that blocks a passage in your body.

    e.g. The boy was suffering from a bowel obstruction and he died.
           这个男孩因患肠梗阻死去了。

3. （通常指对生意、法律或政府的）阻挠，妨碍
    Obstruction is the act of deliberately delaying something or preventing something from happening, usually in business, law, or government.

    e.g. Mr Guest refused to let them in and now faces a criminal charge of obstruction.
           格斯特先生因为将他们拒之门外，现在面临妨碍公务的刑事指控。