Repeat section of repetitive chorus (4)
I believe the answer is:
echo
'repeat' is the definition.
(synonyms)
'section of repetitive chorus' is the wordplay.
'section of' indicates the answer is hidden within the clue.
'ECHO' can be found hidden inside 'repetitive chorus'.
(Other definitions for echo that I've seen before include "One who slavishly copies" , "Reverberation of sound" , "Reiterate" , "call back" , "copy" .)