Pear-shaped stringed instrument (4)
I believe the answer is:
lute
'pear-shaped stringed instrument' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lute that I've seen before include "Old guitar-like instrument played by minstrels" , "Subject to drugs" , "Old musical instrument" , "clay" , "Plucked, pear-shaped instrument" .)