Organist somehow dressing down (8)
I believe the answer is:
Here is my best explanation:
'dressing down' is the definition.
'roasting' can be an answer for 'dressing' (thesaurus). I'm not sure about the 'down' bit.
'organist somehow' is the wordplay.
'somehow' indicates anagramming the letters.
'organist' anagrammed gives 'ROASTING'.