Doreen's dodgy back (7)
I believe the answer is:
endorse
'back' is the definition.
(synonyms)
'doreen's dodgy' is the wordplay.
'dodgy' indicates an anagram.
'doreens' is an anagram of 'ENDORSE'.
(Other definitions for endorse that I've seen before include "Uphold" , "Countersign" , "No reeds (anag)" , "Give backing to" , "Give public approval of (something)" .)