Domesticated bird (4)
I believe the answer is:
fowl
'domesticated bird' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for fowl that I've seen before include "Bird to be eaten or hunted as game" , "Any farmyard bird" , "Poultry bird" , "Bird, maybe domestic" , "Bird kept for eggs and meat" .)