Retreating supporters? (7)
I believe the answer is:
backing
'retreating' is the definition.
The answer and definition can be both to do with motion as well as being present participle verbs.
Perhaps there's an association between them I don't understand?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for backing that I've seen before include "change of wind" , "promotion" , "Withdrawing" , "Endorsement" , "funds?" .)