Charlie Bishop fed with old loaf (3)
I believe the answer is:
cob
'loaf' is the definition.
(I've seen this before)
'charlie bishop fed with old' is the wordplay.
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'bishop' becomes 'B' (chess abbreviation).
'fed with' is an insertion indicator.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'c'+'b'='cb'
'cb' placed around 'o' is 'COB'.
(Other definitions for cob that I've seen before include "mixture of clay and straw" , "Source of bread" , "mount" , "A loaf; a nut; a horse" , "Round loaf of bread" .)