Subtle satire occasionally stops oppression (8)
I believe the answer is:
abstruse
'subtle' is the definition.
(thesaurus)
'satire occasionally stops oppression' is the wordplay.
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
'stops' means one lot of letters goes inside another (stopping can mean blocking a gap).
'oppression' becomes 'abuse' (I can't explain this - if you can you should believe this answer much more).
The alternate letters of 'satire' are 'str'.
'str' going within 'abuse' is 'ABSTRUSE'.
Can you help me to learn more?
(Other definitions for abstruse that I've seen before include "Difficult to understand, obscure" , "Hard to understand, recondite" , "Busts are oddly difficult to understand" , "Incomprehensible to those with normal understanding" , "Difficult to comprehend" .)