Fizzy drink accordingly put next to prosecutor (4)
I believe the answer is:
soda
'fizzy drink' is the definition.
(soda is a fizzy drink)
'accordingly put next to prosecutor' is the wordplay.
'accordingly' becomes 'so' (synonyms).
'put next to' is a charade indicator (letters next to each other).
'prosecutor' becomes 'D.A.' (District Attorney).
'so'+'da'='SODA'
(Other definitions for soda that I've seen before include "Alkaline substance used in cleaning, drinks etc" , "Whisky mixer" , "Splash served with some spirits" , "In the US, a sweet fizzy drink" , "Soft drink" .)