Bar in US city supplying dope (5)
I believe the answer is:
ninny
'dope' is the definition.
(thesaurus)
'bar in us city' is the wordplay.
'bar' becomes 'inn' (I've seen this before**).
'in' is an insertion indicator.
'us city' becomes 'ny' (I've seen this in other clues).
'inn' placed within 'ny' is 'NINNY'.
'supplying' acts as a link.
(Other definitions for ninny that I've seen before include "Fool" , "not a wise man" , "gravely so miscalled by mechanicals" , "Silly billy" , "Simpleton" .)