Problem bar got overwhelming prohibition (7)
I believe the answer is:
embargo
'prohibition' is the definition.
(thesaurus)
'problem bar got overwhelming' is the wordplay.
'overwhelming' indicates a hidden word (the clues covers up or 'overwhelms' the answer).
'EMBARGO' is hidden within 'problem bar got'.
(Other definitions for embargo that I've seen before include "Official prohibition as on trade" , "Trading restriction" , "Eg, Rambo? (anag)" , "Restraint - prohibition" , "Ban or restraint on trade" .)