Supporter of something wicked (6)
I believe the answer is:
sconce
'supporter' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sconce that I've seen before include "Light holder" , "Student challenge" , "Wall-mounted candle holder" , "fine at university" , "Candle bracket - earthwork - head" .)