To block up; to stop up or close; as a way or passage; to fill with obstacles or impediments that prevent passing; as, to obstruct a road, highway or channel; to obstruct the canals or fine vessels of the body.

To stop; to impede; to hinder in passing; as, the bar at the mouth of the river obstructs the entrance of ships; clouds obstruct the light of the sun.

To retard; to interrupt; to render slow. Progress is often obstructed by difficulties, though not entirely stopped.