Small Hawaiian guitar (7)
I believe the answer is:
ukulele
'small hawaiian guitar' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ukulele that I've seen before include "George Formby's thing?" , "Instrument from Hawaii" , "Small 4-stringed guitar" , "Eek - Lulu! (anag)" , "Small, four-stringed guitar" .)