Obstruction - cessation (8)
I believe the answer is:
stoppage
I believe this is a double definition.
'obstruction' is the first definition.
(I know that stoppage is a type of obstruction)
'cessation' is the second definition.
(I've seen this in another clue)
(Other definitions for stoppage that I've seen before include "pay may be reduced by this" , "Obstructed condition" , "What plug achieves" , "Closure" , "Onstruction in pipe or interruption in game" .)