Guitar ridge (4)
I believe the answer is:
fret
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">guitar ridge</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for fret that I've seen before include "Worry or agitate" , "Worry unnecessarily" , "Mist coming in from the sea" , "Worry; sort of saw" , "coastal mist" .)