Copy Spain and Switzerland, love (4)
I believe the answer is:
Here is my best explanation:
'copy' is the definition.
'spain and switzerland love' is the subsidiary indication.
'spain' becomes 'e' (abbreviation for Espania).
'and' means one lot of letters go next to another.
'switzerland' becomes 'ch'.
'love' becomes 'o' (In tennis, 'love' means 'zero').
(Other definitions for echo that I've seen before include "Repetition by reflection", "Comms code word for E", "Sound reverberation", "Reflect in Czechoslovakia", "Reflected sound", "Close imitation", "Parrot", "Sound return", "She loved Narcissus - it's recalled" and "Imitate -- a nymph".)