Shut up about grand echo (4)
I believe the answer is:
cage
'shut up' is the definition.
(I've seen this in other clues)
'about grand echo' is the wordplay.
'about' becomes 'ca' (abbreviation for circa).
'grand' becomes 'g' (G is short for grand as in a thousand).
'echo' becomes 'e' (phonetic alphabet: alpha, bravo, charlie etc.).
'ca'+'g'+'e'='CAGE'
(Other definitions for cage that I've seen before include "US avant-garde composer, d. 1992" , "Enclose with bars" , "Nicolas - - (films)" , "Put behind bars" , "John ---, composer; one with bars" .)