Officer has American drink (4)
I believe the answer is:
cola
'drink' is the definition.
(cola is a kind of drink)
'officer has american' is the wordplay.
'officer' becomes 'col' (I've seen this before**).
'has' is a charade indicator (letters next to each other).
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'col'+'a'='COLA'
(Other definitions for cola that I've seen before include "Cold drink" , "Fizzy drink" , "pop" , "Carbonated soft drink" .)