Peas, for a pea shooter (4)
I believe the answer is:
ammo
'peas for a pea shooter' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ammo that I've seen before include "Slugs perhaps" , "explosives, perhaps" , "Bullets and bombs, etc (abbr)" , "Bullets (abbrev.)" , "Bullets, shells, rockets etc" .)