Banjo sound
I believe the answer is:
twang
'banjo sound' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for twang that I've seen before include "Local intonation" , "Nasal tone or sound of plucked string" , "Sharp vibrating sound" , "Sound of a tense wire or bowstring being plucked" , "Strongly nasal quality in speech" .)