Instrument, possible collector's piece (5)
I believe the answer is:
cello
'instrument' is the definition.
(cello is a kind of instrument)
'possible collector's piece' is the wordplay.
'CELLO' is hidden backwards within the letters.
But, I am unsure how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for cello that I've seen before include "String quartet instrument" , "Bass stringed instrument" , "Tortelier's instrument" , "Musical instrument like large violin held between knees" , "Casals' instrument" .)