Part of a guitar
I believe the answer is:
fret
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">part of a guitar</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know this)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for fret that I've seen before include "Worry - ridge on guitar's fingerboard" , "Harry - on the guitar" , "Worry - bar on the fingerboard of a stringed instrument" , "Be anxious -- part of a fingerboard" , "ridge > that obscures sea view" .)