European trophies over bar (5)
I believe the answer is:
estop
'bar' is the definition.
(thesaurus)
'european trophies over' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'trophies' becomes 'pots'.
'over' is a reversal indicator.
'pots' backwards is 'stop'.
'e'+'stop'='ESTOP'
(Other definitions for estop that I've seen before include "Preclude certain evidence (at law) - bar (archaic)" , "term in law" , "Bar, for a lawyer" , "Hinder, preclude (law)" , "Legally prevent" .)