At intervals, went round educational establishment (4)
I believe the answer is:
eton
'educational establishment' is the definition.
The definition suggests a singular noun which matches the answer.
'at intervals went round' is the wordplay.
'at intervals' indicates alternate letters (letters are taken at regular intervals).
'went'+'round'='wentround'
The alternating letters of 'wentround' are 'ETON'.
Can you help me to learn more?
(Other definitions for eton that I've seen before include "School near Slough" , "Public school near Windsor" , "Kind of collar or jacket (worn at college?)" , "collar, perhaps?" , "Note sent up to English public school" .)