School set up record (4)
I believe the answer is:
note
'record' is the definition.
(note is a kind of record)
'school set up' is the wordplay.
'school' becomes 'eton' (famous UK public school).
'set up' shows that the letters should be reversed in order.
'eton' written backwards gives 'NOTE'.
(Other definitions for note that I've seen before include "Brief letter - distinction" , "A flat, for example" , "Comment" , "Short written message" , "Crotchet or minim, perhaps" .)