Worrisome guitar part? (4)
I believe the answer is:
fret
'worrisome guitar part?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for fret that I've seen before include "Worry unnecessarily" , "Harry - on the guitar" , "Wear away" , "Worry - ridge on guitar's fingerboard" , "Guitar ridge; be anxious" .)