Canyon feedback (4)
I believe the answer is:
echo
'canyon feedback' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for echo that I've seen before include "Parrot" , "Reproduction" , "Repeated sound" , "Greek nymph, spurned by Narcissus, who pined away until only her voice remained" , "copy" .)