Chicken or duck
I believe the answer is:
fowl
This clue is a double definition.
'chicken' is the first definition.
(chicken is a type of fowl)
'duck' is the second definition.
(thesaurus)
(Other definitions for fowl that I've seen before include "Poultry bird" , "Domestic birds" , "eg hen" , "eg Chicken" , "Cock or hen" .)