EU minister opening function turned up late (7)
I believe the answer is:
overdue
'late' is the definition.
(similar in meaning)
'eu minister opening function turned up' is the wordplay.
'minister' becomes 'rev' (short for reverend).
'opening' indicates putting letters inside (some letters open a gap in others).
'function' becomes 'do' (both can mean an event).
'turned up' says the letters should be written backwards.
'rev' put into 'do' is 'drevo'.
'eu'+'drevo'='eudrevo'
'eudrevo' written backwards gives 'OVERDUE'.
(Other definitions for overdue that I've seen before include "Belated" , "Past the ETA" , "Not paid by the appropriate time" , "Late like unpaid bill" , "Remaining unpaid after the scheduled time" .)