Treacherous revolutionary initially escaping capture in retreat (6)
I believe the answer is:
rotten
'treacherous' is the definition.
Both the definition and answer are adjectives. Perhaps there's an association between them I don't understand?
'revolutionary initially escaping capture in retreat' is the wordplay.
'initially' suggests taking the first letters.
'escaping capture' becomes 'netto' (I can't explain this - if you can you should believe this answer much more).
'in retreat' says the letters should be written in reverse.
The first letter of 'revolutionary' is 'r'.
'netto' reversed gives 'otten'.
'r'+'otten'='ROTTEN'
Can you help me to learn more?
(Other definitions for rotten that I've seen before include "Decomposed" , "Falling to pieces from age or morally contemptible" , "unpleasant" , "Something is ... in the state of Denmark (Hamlet)" , "'Gone bad, decayed (6)'" .)