Four-stringed instrument
I believe the answer is:
ukulele
'four-stringed instrument' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ukulele that I've seen before include "George Formby's little guitar" , "One needs pluck in this" , "Musical instrument once played by George Formby" , "play this?" , "Small 4-stringed guitar" .)