Turkey perhaps unpalatable, by the sound of it (4)
I believe the answer is:
fowl
'turkey perhaps' is the definition.
(turkey is a kind of fowl)
'unpalatable by the sound of it' is the wordplay.
'unpalatable' becomes 'foul'.
'by the sound of it' shows a homophone (sound like).
'foul' is a homophone of 'FOWL'.
(Other definitions for fowl that I've seen before include "Domesticated bird" , "Poultry bird" , "Any farmyard bird" , "eg hen" , "eg Chicken" .)