Large stringed instrument (5)
I believe the answer is:
cello
'large stringed instrument' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for cello that I've seen before include "Large stringed instrument" , "big fiddle?" , "Musical instrument like large violin held between legs" , "It's bigger than a viola, but smaller than a double bass" , "large-scale fiddle" .)