Elation centred around European agreement (7,8)
I believe the answer is:
entente cordiale
'agreement' is the definition.
(entente cordiale is a kind of agreement)
'elation centred around european' is the wordplay.
'around' indicates anagramming the letters.
'european' becomes 'e' (abbreviation e.g. EU).
'elation'+'centred'='elationcentred'
'elationcentred' anagrammed gives 'ententecordial'.
'ententecordial'+'e'='ENTENTE CORDIALE'
(Other definitions for entente cordiale that I've seen before include "Understanding" , "Agreement" .)