Old citizen's article connected with prohibition (6)
I believe the answer is:
theban
'old citizen's' is the definition.
(I've seen this before)
'article connected with prohibition' is the wordplay.
'article' becomes 'the' (the definite article).
'connected with' is a charade indicator (letters next to each other).
'prohibition' becomes 'ban' (synonyms).
'the'+'ban'='THEBAN'
(Other definitions for theban that I've seen before include "Native of one ancient Greek or Egyptian city" , "Nab the person from the ancient Greek city" , "Relating to an ancient Greek city" , "Old citizen" , "ancient Greek citizen" .)