Good day to see ducks around US state (4)
I believe the answer is:
ohio
'us state' is the definition.
(I've seen this before)
'good day to see ducks around' is the wordplay.
'good day' becomes 'hi'.
'to see ducks' becomes 'OO' (two O's - duck means zero in cricket).
'around' is an insertion indicator.
'hi' placed inside 'oo' is 'OHIO'.
(Other definitions for ohio that I've seen before include "American state, capital Columbus" , "Midwest US state" , "E. central US state" , "State of the union" , "state of America" .)