A resounding comeback (4)
I believe the answer is:
echo
This clue is a double definition.
'a resounding' is the first definition.
(thesaurus)
'comeback' is the second definition.
(I've seen this in another clue)
(Other definitions for echo that I've seen before include "repeated answer" , "Trace call" , "Repetition of sound" , "Reproduction" , "Reiterate" .)