Picnic discard (3)
I believe the answer is:
cob
'picnic discard' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cob that I've seen before include "Hazelnut" , "Horse, male swan and loaf of bread" , "mount" , "Round loaf of bread" , "mixture of clay and straw" .)