Set of items put behind somewhere filthy for hairdresser (7)
I believe the answer is:
stylist
'somewhere filthy for hairdresser' is the definition.
'stylist' can be an answer for 'hairdresser' (synonyms). I am not sure about the 'somewhere filthy for' bit.
'set of items put behind' is the wordplay.
'set of' becomes 'styli' (I can't explain this - if you can you should give a lot more credence to this answer).
'behind' suggests the final letters.
The last letters of 'items put' are 'st'.
'styli'+'st'='STYLIST'
Can you help me to learn more?
(Other definitions for stylist that I've seen before include "Good writer" , "Fashion expert" , "Designer of fashionable clothing" , "Clothes designer; hairdresser" , "One who shapes or designs, say hair-do" .)