Ancient Greek stringed instrument (4)
I believe the answer is:
lyre
'ancient greek stringed instrument' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for lyre that I've seen before include "Harp used by ancient Greeks" , "Ancient harp-like instrument" , "Music-maker" , "Plucked instrument" , "Ancient Greece harp" .)