Not in front of the supporters (9)
I believe the answer is:
following
'front of the supporters' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'not in' is the wordplay.
I cannot quite understand how this works, but
'not' could be 'o' (I've seen this in other clues) and 'o' is located in the answer.
'in' is within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for following that I've seen before include "Next after" , "Understanding" , "about to be mentioned" , "Body of supporters" , "Coming after" .)