Old stringed instrument from hilly region (4)
I believe the answer is:
lyre
'old stringed instrument' is the definition.
(I've seen this in another clue)
'from hilly region' is the wordplay.
'from' says the answer is hidden in the clue.
'LYRE' is hidden within 'hilly region'.
(Other definitions for lyre that I've seen before include "Old musical instrument with strings in U-shaped frame" , "Harp used by ancient Greeks" , "Old instrument, like a harp" , "Ancient musical instrument - sounds mendacious" , "Ancient Greek harp" .)