EU partner ruined entrance (9)
I believe the answer is:
enrapture
'entrance' is the definition.
(thesaurus)
'eu partner ruined' is the wordplay.
'ruined' is an anagram indicator.
'eu'+'partner'='eupartner'
'eupartner' is an anagram of 'ENRAPTURE'.
(Other definitions for enrapture that I've seen before include "Give intense pleasure to" , "entrance" , "Bewitch" , "Transport" , "Ape Turner (anag.)" .)