Celebrated day school being over (5)
I believe the answer is:
noted
'celebrated' is the definition.
('noted' can be a synonym of 'celebrated')
'day school being over' is the wordplay.
'day' becomes 'd'.
'school' becomes 'eton' (famous UK public school).
'being over' says the letters should be written backwards.
'd'+'eton'='deton'
'deton' backwards is 'NOTED'.
(Other definitions for noted that I've seen before include "Toned (anag.)" , "Famous or eminent" , "Celebrity" , "Remarkable" , "Famous, well-known - entered into little book" .)