Nothing like a duck (3)
I believe the answer is:
nil
I believe this is a double definition.
'nothing' is the first definition.
(eg nil is zero in football)
'duck' is the second definition.
(both can mean zero)
'like a' is the link.
(Other definitions for nil that I've seen before include "There's nothing left" , "Lacking value" , "Don't despair - . . . desperandum" , "0" , "duck" .)