Gestapo quietly organised a strike (8)
I believe the answer is:
stoppage
'a strike' is the definition.
(I've seen this before)
'gestapo quietly organised' is the wordplay.
'quietly' becomes 'p' (p for piano and quiet).
'organised' is an anagram indicator.
'gestapo'+'p'='gestapop'
'gestapop' with letters rearranged gives 'STOPPAGE'.
(Other definitions for stoppage that I've seen before include "Refusal to work" , "Onstruction in pipe or interruption in game" , "What plug achieves" , "strike results" , "Instance of industrial action" .)