Wind instrument or a loud stringed one (5)
I believe the answer is:
flute
'wind instrument' is the definition.
(I know that flute is a type of woodwind instrument)
'a loud stringed one' is the wordplay.
'a loud' becomes 'f' (short for forte - 'loud' in music).
'stringed one' becomes 'lute' (I can't justify this - if you can you should give a lot more credence to this answer).
'f'+'lute'='FLUTE'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for flute that I've seen before include "Wind instrument" , "Champagne glass" , "Blown" , "Narrow wineglass" , "Musical instrument - wineglass" .)