Carelessly dropped rubbish (6)
I believe the answer is:
litter
'carelessly dropped rubbish' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for litter that I've seen before include "Animal young, stretcher and rubbish" , "Carelessly dropped rubbish" , "New-born animals" , "Scatter rubbish around" , "Not a neat" .)