Hang onto pig (3)
I believe the answer is:
hog
I believe this clue is a double definition.
'hang onto' is the first definition.
(both can mean to keep for oneself)
'pig' is the second definition.
(I know that pig can be written as hog)
(Other definitions for hog that I've seen before include "Pig; hoard selfishly" , "Pig reared for slaughter" , "Take greedily" , "Monopolise" , "Domesticated pig" .)