Obstacle or blockage (11)
I believe the answer is:
obstruction
I believe this is a double definition.
'obstacle' is the first definition.
(I know that obstacle can be written as obstruction)
'blockage' is the second definition.
(I know that blockage can be written as obstruction)
(Other definitions for obstruction that I've seen before include "Hindrance to progress" , "Barrier" , "Blockage" , "bar" .)