Drop litter and stuff (3)
I believe the answer is:
Here is my best explanation:
I believe this clue is a double definition.
'drop litter' is the first definition.
('pig' can mean to give birth to a litter of pigs)
'stuff' is the second definition.
(both can mean to eat lots of food)
'and' acts as a link.
(Other definitions for pig that I've seen before include "Greedy person (colloq.)", "Eg, sow", "Unforged metal", "Greedy eater", "Farmyard animal", "quantity", "Boar or sow", "Eat greedily", "Glutton" and "Difficult task".)