Echo a lot at school (4)
I believe the answer is:
eton
'school' is the definition.
(famous UK public school)
'echo a lot' is the wordplay.
'echo' becomes 'e' (phonetic alphabet: alpha, bravo, charlie etc.).
'a lot' becomes 'ton' (I've seen this in another clue).
'e'+'ton'='ETON'
'at' acts as a link.
(Other definitions for eton that I've seen before include "Leading English public school" , "School - note (anag)" , "Posh college" , "Posh British public school" , "Public school founded by Henry VI" .)