The setter backing his editor to provide raise? (6)
I believe the answer is:
emboss
'raise?' is the definition.
(thesaurus)
'the setter backing his editor' is the wordplay.
'the setter backing his' becomes 'em' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'editor' becomes 'boss' (editor is a type of boss).
'em'+'boss'='EMBOSS'
'to provide' acts as a link.
(Other definitions for emboss that I've seen before include "Carve or mould a design to stand out in relief" , "Bring about relief" , "Ornament in relief" , "opposite of grave" , "Make a raised carving" .)