Drunk topes in bar (5)
I believe the answer is:
estop
'bar' is the definition.
(thesaurus)
'drunk topes' is the wordplay.
'drunk' indicates an anagram.
'topes' with letters rearranged gives 'ESTOP'.
'in' is the link.
(Other definitions for estop that I've seen before include "Preclude certain evidence (at law) - bar (archaic)" , "Legally hinder removal" , "lawyer's bar" , "term in law" , "Legally prevent" .)