Rascal with mop going bald, hurt (6)
I believe the answer is:
impair
'bald hurt' is the definition.
'impair' can be an answer for 'hurt' (I've seen this in another clue). I am unsure of the 'bald' bit.
'rascal with mop going' is the wordplay.
'rascal' becomes 'imp' (synonyms).
'with' is a charade indicator (letters next to each other).
'mop going' becomes 'air' (I can't explain this - if you can you should give a lot more credence to this answer).
'imp'+'air'='IMPAIR'
Can you help me to learn more?
(Other definitions for impair that I've seen before include "blunt" , "Spoil, degrade" , "Hobble" , "Weaken, damage" , "'Mar, damage (6)'" .)