Prohibition — where can you get a drink? (3)
I believe the answer is:
bar
I believe this clue is a double definition.
'prohibition' is the first definition.
(thesaurus)
'where can you get a drink?' is the second definition.
(bars serve drinks)
(Other definitions for bar that I've seen before include "Exclude; sandbank" , "Stop" , "A pub counter, or barristers' profession" , "Local" , "Sandbank; prohibit" .)