Impose ban on criminal tried in court (9)
I believe the answer is:
interdict
'impose ban on' is the definition.
(interdict can mean to ban something)
'criminal tried in court' is the wordplay.
'criminal' is an anagram indicator.
'court' becomes 'ct' (abbreviation used in road names).
'tried'+'in'='triedin'
'triedin' with letters rearranged gives 'interdi'.
'interdi'+'ct'='INTERDICT'
(Other definitions for interdict that I've seen before include "Credit tin (anag) - ecclesiastical sanction" , "Court order" , "Decree" , "Ban" , "Prohibit - tin credit (anag)" .)