Duck or goose (4)
I believe the answer is:
fowl
I believe this clue is a double definition.
'duck' is the first definition.
(thesaurus)
'goose' is the second definition.
(thesaurus)
(Other definitions for fowl that I've seen before include "eg hen" , "Cock or hen" , "Domestic birds" , "Any farmyard bird" , "Bird kept for eggs and meat" .)