Code word for E (4)
I believe the answer is:
echo
'code word for e' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for echo that I've seen before include "A natural sound reflection" , "In The Maid of the Mountains" , "Be suggestive of" , "Nymph (only able to repeat the last words of others)" , "Greek girl in love with Narcissus" .)