Powerful supporter of Charlton? (8)
I believe the answer is:
athletic
I believe this is a triple definition!
'powerful' is the first definition.
(I've seen this before)
'supporter' is the second definition.
(thesaurus)
'of' acts as a link.
'charlton?' is the third definition.
(I know that Charlton Athletic F.C. can be written as Athletic)
(Other definitions for athletic that I've seen before include "Good at physical games" , "Physically fit, strong and active" , "Lithe act (anag)" , "Given to partaking in sporting events" , "Team" .)