Rubbish dropper (9)
I believe the answer is:
litterbug
'rubbish dropper' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for litterbug that I've seen before include "One likely to drop" , "Trash dropper" , "Person wilfully dropping rubbish" , "One leaving papers around" , "Inconsiderately, one drops" .)