A grand on European match (5)
I believe the answer is:
agree
'match' is the definition.
(agreeing is a kind of matching)
'a grand on european' is the wordplay.
'a grand' becomes 'ag' (I've seen this in other clues).
'on' becomes 're' ('on' can be mean 'with reference to').
'european' becomes 'e' (abbreviation e.g. EU).
'ag'+'re'+'e'='AGREE'
(Other definitions for agree that I've seen before include "Concur, coincide" , "Consent required" , "Shake on it" , "Allow" , "'Birds in their little nest . . . . .'" .)