Former Communist hiding service in Revolution (7)
I believe the answer is:
retired
'former' is the definition.
(eg a retired footballer is a former footballer)
'communist hiding service in revolution' is the wordplay.
'communist' becomes 'red' (red is a kind of communist).
'hiding' means one lot of letters goes inside another.
'service' becomes 'rite' (I've seen this before).
'in revolution' is a reversal indicator.
'rite' reversed gives 'etir'.
'red' placed around 'etir' is 'RETIRED'.
(Other definitions for retired that I've seen before include "No longer active in work or profession" , "No longer working" , "Pensioned off" , "Finished work" , "Gone to bed" .)