Closed deals arranged with European (6)
I believe the answer is:
sealed
'closed' is the definition.
(associated in meaning)
'deals arranged with european' is the wordplay.
'arranged with' indicates an anagram.
'european' becomes 'E' (abbreviation e.g. EU).
'deals' mixed up with 'e' can make 'SEALED'.
(Other definitions for sealed that I've seen before include "Stamped as authentic" , "Fastened as in S.W.A.L.K." , "Securely fastened" , "Shut up tight" , "Securely closed" .)