A load of binned rubbish sent back (6)
I believe the answer is:
burden
'a load' is the definition.
(I know that load can be written as burden)
'of binned rubbish sent back' is the wordplay.
'of' indicates a hidden word.
'sent back' says the letters should be written backwards.
'nedrub' is hidden within 'binned rubbish'.
'nedrub' back-to-front is 'BURDEN'.
(Other definitions for burden that I've seen before include "Unwelcome load" , "Weigh down - load" , "Encumbrance" , "Oppressive duty" , "Load or responsibility carried" .)