the fact of trying to prevent something/somebody from making progress

the fact of blocking a road, an entrance, a passage, etc.

The abandoned car was causing an obstruction.

something that blocks a road, an entrance, etc.

It is my job to make sure that all pathways are clear of obstructions.

something that blocks a passage or tube in your body; a medical condition resulting from this

He had an operation to remove an obstruction in his throat.

bowel/intestinal obstruction

the offence of unfairly putting your body in front of a player of the other team so they cannot move to get the ball

LEARNit Dictionary