Aim to move behind revolutionary spy (6)
I believe the answer is:
target
'aim' is the definition.
(synonyms)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for target that I've seen before include "A result to aim at" , "aunt Sally" , "Butt" , "Goal; victim" , "Aim, ambition" .)