Bread is crumbled for gannet, say (7)
I believe the answer is:
seabird
'gannet say' is the definition.
(gannet is a kind of seabird)
'bread is crumbled' is the wordplay.
'crumbled' indicates an anagram.
'bread'+'is'='breadis'
'breadis' is an anagram of 'SEABIRD'.
'for' is the link.
(Other definitions for seabird that I've seen before include "A gull, for instance" , "Gannet possibly" , "Gull perhaps" , "gannet, perhaps" , "Marine creature" .)